BEIRUT, Lebanon -- Disjointed diplomatic maneuvering on the Syria crisis by top foreign officials on Tuesday seemed to underscore the lack of any coherent international effort to end the fighting, even as another residential bombing and an assassination rocked Damascus.
"The situation inside Syria is turning grimmer every day, and the risk is growing that this crisis could explode outward into an already volatile region," Jeffrey D. Feltman, the United Nations under-secretary-general for political affairs, told a meeting of the Security Council.
Underscoring that threat, Israel accused Syria of moving tanks into a demilitarized zone of the disputed Golan Heights region captured by the Israelis in the 1967 war and asked the Security Council to address "this alarming development." Mr. Feltman, who answered questions from reporters at the United Nations, said he was concerned about the new Golan tension and called it "another example of spillover from areas that had been previously immune from fighting."
Mr. Feltman also quoted activists as saying that 250 people had died across Syria on Monday. "We continue to hope that the Security Council can come together and act in a unified fashion on Syria, as this would be critical to any peace effort," he said.
There was no sign of that.
The Russian foreign minister, Sergey V. Lavrov, held talks in Jordan with the highest-ranking defector from the Syrian government, former Prime Minister Riad Hijab, who attacked Moscow's enduring support for President Bashar al-Assad as unworkable for a political transition.
Remarks by David Cameron, the British prime minister, that Mr. Assad might be granted safe passage out of his country as a means to end the fighting also caused a stir, with his office quickly stressing that he did not mean Mr. Assad should avoid prosecution.
Lakhdar Brahimi, the international envoy to the conflict, warned that unless there was a greater international effort, Syria risked descending into another Somalia -- which as a failed state became a font of international piracy and other terrorist problems for 20 years. In an interview with the pan-Arab newspaper Al-Hayat, Mr. Brahimi said the main effort should be a binding Security Council resolution on a political transition.
In Damascus, gunmen assassinated the brother of the Syrian Parliament speaker in broad daylight in a central neighborhood, the official Syrian news agency SANA reported.
The victim, Mohammad Osama al-Laham, was felled by bullets fired into his car in the Midan neighborhood while en route to work, SANA said.
The agency attributed the attack to terrorists, the government's standard description for the opposition, and said the motive was to deprive Syria of skilled loyalists needed in the country. Mr. Laham, the brother of Jihad Laham, the speaker of the People's Assembly, held a doctorate in agriculture.
The assassination came one day after the funeral of Mohamed Rafeh, 30, a television star who was abducted and killed, apparently by government opponents, over the weekend. Mr. Rafeh had been outspoken in his support for the fierce government suppression of armed opponents. An online statement from a rebel faction called him an informant.
Other mayhem in the capital and throughout the country included three bombs that exploded late in the day in Qudsiya, a working-class suburb of Damascus, according to SANA and the Syrian Observatory for Human Rights, a group based in Britain with contacts inside Syria.
At least 10 people died and 40 were injured, the observatory said. The bombs exploded in crowded Zahra Square, near an area heavily populated by Republican Guards, an elite military unit whose members are drawn from President Assad's minority Alawite sect that controls Syria. The guards are among the main units used to suppress the opposition.
On Monday, opposition members vowed to step up attacks in the city center to try to draw government units away from extended assaults on other outlying neighborhoods.
"We are planning to escalate our attacks on the areas of the government thugs," said one member of the Jundullah Battalion, a unit of the Free Syrian Army full of Sunni Muslim fundamentalists.
In Amman, Jordan, Mr. Lavrov held a rare meeting between a senior Russian official and the opposition, saying he wanted to glean their thoughts on ending the conflict.
"The idea of the meeting was to get an agreement or a road map on how to deal with opposition forces and save the Syrian people," Mr. Lavrov told a news conference. At the same time, he warned that any alternative to the Assad government might visit further chaos on Syria.
Mr. Hijab rejected that assessment, saying that replacing Mr. Assad was the sole way out of the uprising, which started as a peaceful protest movement in March 2011.
"Russia is searching for a political solution in which Bashar al-Assad stays," he said in an interview with Al-Arabiya, an Arabic satellite television station. "We told Lavrov frankly that there could be no political solution at all with the presence of Bashar al-Assad."
On a visit to Saudi Arabia and the Gulf, Mr. Cameron told Al-Arabiya in an interview that if safe passage and possibly immunity for Mr. Assad would end the bloodshed, it might be negotiated.
"I am certainly not offering him an exit plan to Britain, but if he wants to leave he could leave, that could be arranged," said Mr. Cameron. "Of course I would favor him facing the full force of international law and justice for what he's done."
Mr. Assad has shown no intention of going anywhere. Indeed, analysts have long said that the fact that he inherited the presidency from his father prompted him to destroy Syria rather than abandon his legacy.
The lack of a cohesive Syrian opposition has been blamed for preventing a more robust international effort on Syria. Attempts to create a more unified coalition sputtered along Tuesday in Doha, Qatar, where a meeting was scheduled for Thursday to try to implement an American-backed plan to broaden the opposition to include more factions, including more representatives of the military units doing the fighting.
On that front, news agencies in Turkey reported that seven Syrian Army generals arrived with their families through the border town of Reyhanli in Hatay Province, escorted under tight security.
The generals were sent to the Apaydin military camp, home to high-ranking military officers and their families who have fled Syria. The Turkish newspaper Zaman reported on its Web site that the latest defections brought the total number of Syrian generals who have defected to 42.
Reporting was contributed by Hania Mourtada from Beirut, Lebanon, Rick Gladstone from New York and Hwaida Saad from Antakya, Turkey.
This article originally appeared in The New York Times.