NAIROBI, Kenya -- The Kenyan government on Sunday night appeared ready to storm Shabab militant attackers holed up in a mall for more than a day, seeking to end a siege that has shaken the nation and left dozens dead.
As helicopters circled the Westgate mall in Nairobi, the National Disaster Operation Center said on Twitter Sunday evening after sunset: "Godspeed to our guys in the Westgate building. Major engagement ongoing. Sporadic gunfire."
"Kenyan forces who've just attempted a roof landing must know that they are jeopardising the lives of all the hostages at #Westgate," read a Twitter post attributed to the Shabab on Sunday night. "The Kenyan government shall be held responsible for any loss of life as a result of such an imprudent move."
It was unclear the extent or goals of the incursion. At least four explosions could be heard Sunday night near Westgate, though the area was cordoned off.
Earlier in the day, the Kenyan president, Uhuru Kenyatta, addressed the nation urging patience and expressing sorrow atloss of life.
"I am aware that many have expressed impatience over the pace at which the situation is unfolding," he said. "And while I empathize with your anxiety at seeing the matter concluded as quickly as possible, I ask also for understanding."
Mr. Kenyatta said that more than 1,000 people had been rescued from the mall at the time of the attack, calling it "remarkable and encouraging." But the death toll from the militant assault on the crowded Westgate mall the day before continued to rise, climbing to 68, according to the Red Cross. Among them were Mr. Kenyatta's nephew and the nephew's fiancée, he said in his speech.
"These are young, lovely people I personally knew and loved," Mr. Kenyatta said. "Many of us have lost loved ones. Let us mourn them all as one nation and keep them always in remembrance and prayer."
Joseph Ole Lenku, the cabinet secretary for the interior, said on Sunday that the number of wounded was at least 175, though many had been treated and discharged. "Overnight more people were evacuated from the mall, but a number still remain," he said. "The government will go out of its way to make sure we do not lose lives."
A huge contingent of Kenyan security forces kept the mall cordoned off Sunday, but officials confirmed that many attackers -- 10 to 15, according to Mr. Lenku -- were still inside and active, and that an uncertain number of bystanders remained trapped or in hiding.
The Kenya Red Cross, citing the police as their source, said that the number of missing persons was 49, raising the prospect of a significantly higher death toll before the crisis is ended.
The prospect of more violence on Sunday was tangible, even as a deeply shaken public began to come to grips with the toll already inflicted.
The identities of several victims began to come out Sunday, and with it the public mourning of a national tragedy had begun. The local news media reported that a popular radio host was among those killed, as was a noted poet and professor from Ghana.
The radio host, Ruhila Adatia-Sood, was in the parking lot of the Westgate mall, where she was hosting a cooking competition, according to reports. She had posted several photos on her Instagram account before the attack.
Also among the dead was Kofi Awoonor, 78, the Ghanaian poet and former professor at the University of Ghana. He was also the former chairman of the Council of State.
The mall is a symbol of Kenya's rising prosperity, an impressive five-story building where Kenyans can buy expensive cups of frozen yogurt and plates of sushi. On Saturdays, it is especially crowded, and American officials have long warned that Nairobi's malls were ripe targets for terrorists.
Fred Ngoga Gateretse, an official with the African Union, was having coffee at the ArtCaffe coffee shop on the ground floor around noon on Saturday when he heard two deafening blasts. He said he had crouched on the floor and watched eight gunmen with scarves twisted over their faces firing at shoppers and then up at Kenyan police officers who were shooting down from a balcony as panicked shoppers dashed for cover. "Believe me, these guys were good shooters," Mr. Gateretse said. "You could tell they were trained."
Even as the fight continued into Sunday afternoon, with the attackers contained to the mall's third floor, the Kenyan news media reported that one wounded gunman had been captured and died in a hospital. Several witnesses also said one of the attackers was a woman.
Several witnesses said the attackers had shouted for Muslims to run away while they picked off other shoppers, executing them one by one. The mall, one of Nairobi's most luxurious, with glass elevators and some of the most expensive shops in town, is also popular with expatriates. It has served as the place for a power lunch, to catch a movie, to bring children for ice cream.
Four Americans were believed to have been injured in the attack, American officials said, and none were reported killed. Secretary of State John Kerry, who called the attack "a heartbreaking reminder that there exists unspeakable evil in our world," said the wife of a local employee of the American government was among the dead. Two Canadians, one of them a diplomat based in Nairobi, and two French citizens were killed, their governments said.
Ilana Stein, a spokeswoman for Israel's Ministry of Foreign Affairs, said the attack initially took place near the ArtCaffe, an Israeli-owned coffee shop and bakery popular with foreigners that is one of 80 businesses in the mall. Ms. Stein said that one Israeli had been lightly injured, that three others had escaped unharmed and that Israelis had not been specifically targeted. "This time, the story is not about Israel," Ms. Stein said.
On Sunday, Israeli officials denied reports that the country's security services had gotten involved in the standoff in Nairobi. But a report on the news site Ynet cited a senior Israeli security source as saying that Israeli "consultants" had been helping the Kenyans "formulate a negotiation strategy to resolve the crisis."
A confidential United Nations security report on Saturday described the mall attack as "a complex, two-pronged assault" with two squads of gunmen dashing into the mall from different floors at the same time and opening fire.
The Shabab, an Islamist militant group based in Somalia, took responsibility for the attack, saying it was revenge for Kenya's military operations in Somalia, which began nearly two years ago. "Kenya will not get peace unless they pull their military out of Somalia," said Ali Mohamoud Rage, the Shabab's spokesman, in a radio address. The Shabab also sent out a barrage of buoyant Twitter messages, bragging about the prowess of their fighters before Twitter abruptly suspended the account late Saturday. Later, a new one was set up.
Mr. Kenyatta called the terrorists cowards and said Kenya would remain "as brave and invincible as the lions on our coat of arms." He also sounded a somber note, pleading with Kenyans to give blood to help the wounded.
Witnesses described attackers using AK-47 and G-3 assault rifles and throwing grenades.
Vivian Atieno, 26, who works on the first floor of the mall, described "intense shooting," starting around 11 a.m., before she escaped through a fire exit.
Haron Mwachia, 20, a cleaner at the mall, said he had survived by climbing over a wall. "I heard several gunshots and managed to run away," he said. "I've never seen anything like it."
Hundreds of relatives and friends of the victims of the attack journeyed to various hospitals around the city that were treating the wounded, trying to ascertain the fate of their loved ones.
At the MP Shah Hospital, a few miles away from the mall, distressed relatives milled around a tent erected for them outside the hospital as volunteers worked around the clock to provide necessary assistance.
Ruth Nyambura, 26, whose uncle worked at the Nakumatt Supermarket in Westgate at the time of the attack, said she was terrified.
"I have come along with my family just to find out how he's doing. He was shot in the head, suffered severe wounds on his one of his eyes and his arms," said Ms. Nyambura. "He was operated yesterday and we've come to see him again. We are being told to wait because the queue is too long."
Kenya serves as the economic engine of East Africa, and while it has been mostly spared the violence and turmoil of many of its neighbors, it has had other terrorist attacks. In 1998, Al Qaeda killed more than 200 people in an enormous truck bombing that nearly leveled the American Embassy in downtown Nairobi, while simultaneously attacking the American Embassy in Dar es Salaam, Tanzania. Islamist terrorists also struck an Israeli-owned hotel on Kenya's Indian Ocean coast in 2002 and fired missiles at an Israeli airliner.
More recently, the Shabab have put Kenya in its cross hairs, especially after Kenya sent thousands of troops into Somalia in 2011 to chase the Shabab away from its borders and then kept those troops there as part of a larger African Union mission to pacify Somalia. The Shabab have attacked churches in eastern Kenya, mosques in Nairobi and government outposts along the Kenya-Somalia border.
But this was the boldest attack yet. Within minutes, as the gunmen opened fire with assault rifles, Westgate was plunged into mayhem and carnage. People ran out screaming, and victims soaking in their own blood were wheeled out in shopping carts. Bodies were still sprawled on the mall's front steps hours afterward, and woozy shoppers continued to emerge from the stores where they had been hiding.
"This is such a shock," said Preeyam Sehmi, an artist, as she stumbled out of the mall, past a phalanx of Kenyan soldiers, after five hours of hiding. "Westgate was such a social place."
Before its Twitter account was shut down, the Shabab sent out a message, saying the fighters in the mall would never give up.
"There will be no negotiations whatsoever at #Westgate," the message said.
The Shabab, who have pledged allegiance to Al Qaeda, used to control large parts of Somalia, imposing a harsh and often brutal version of Islam in their territory. They have beheaded civilians and buried teenage girls up to their necks in sand and stoned them to death. But in the past two years, the African Union forces, including the Kenyans, have pushed the Shabab out of most of their strongholds. The worry now, current and former American officials said Saturday, is that this attack could be the start of a comeback.
"I think this is just the beginning," said Rudy Atallah, the former director of African counterterrorism for the Pentagon. "An attack like this gives them the capability to recruit, it shows off their abilities, and it demonstrates to Al Qaeda central that they are not dead."
Reporting was contributed by Reuben Kyama and Tyler Hicks from Nairobi; Jodi Rudoren from Jerusalem; Mark Mazzetti from Washington; and Mohammed Ibrahim from Mogadishu, Somalia.
This article originally appeared in The New York Times.