BAGHDAD -- Gunmen stormed an apartment complex in Baghdad on Saturday night and killed at least 20 women and six men, according to the Interior Ministry.
The apartment complex is known for prostitution, and in the past prostitutes have been the targets of extrajudicial killings there by Muslim extremists. It was not clear if that was what happened this time. However, if the targets were prostitutes, it is unlikely that would cause the kind of backlash that a large-scale sectarian killing would.
Still the attack, and the fact that at least initially the perpetrators seemed to vanish without a trace, raised the specter that amid the chaos sweeping the country, gunmen feel they can act with complete impunity even in the capital.
Almost at the same time, a television station associated with Sunnis broadcast what it said was a recording by Izzat Ibrahim al-Douri, a fugitive who was Saddam Hussein's vice president and a senior figure in the Baath Party.
Intelligence experts have predicted an unleashing of anti-government cells and some wondered on Saturday if Mr. Douri's message was the signal for the cells to begin to fight.
"The liberation of Baghdad has become close or closer," the man reported to be Mr. Douri said in a statement full of support for the insurgency that has swept through large parts of northern and western Iraq. "Half of Iraq's land is outside of the government's control."
The statement was also notable because it appeared to run counter to reports that the insurgency could be weakened by friction between the main insurgent group and Mr. Douri's group of former loyalists to Saddam Hussein.
Mr. Douri is the founder of the Men of the Army of the Naqshbandia Order, a group of former Baathists that has become an active part of the recent battles against the Iraqi government. The broadcast heaped praise on the main Sunni insurgent group, the Islamic State of Iraq and Syria, or ISIS.
"What happened in Nineveh and Tikrit is the greatest day ever in Iraqi and Arab history," the man reported to be Mr. Douri said, referring to the ISIS takeovers, which were carried out with the help of a number of insurgent groups, including the Naqshbandia Order.
He blessed all the groups, but above all "the heroes and knights of al-Qaida and ISIS." He added, "I send them warm greetings full of love."
U.S. and Iraqi officials have been seeking ways to exploit emerging fissures between ISIS and Iraqi extremist groups that allied with it to seize much of northern and western Iraq over the past month.
The groups, which follow the Sunni branch of Islam, made common cause with ISIS, whose members are also Sunni militants, to fight Iraq's Shiite-dominated government. The Shiites are the majority in Iraq, and there is deep distrust between them and the Sunnis.
Recently in Mosul, ISIS has rounded up members of Saddam Hussein's banned Baath Party, whom the group saw as potential rivals. Residents in Salahuddin province are chafing under harsh Islamic law that ISIS has already started putting in place. Former Baathists are suspected in last week's assassination of the ISIS emir in Diyala province.
In short, the marriages of convenience formed among ISIS and Baathists, Sunni nationalists, Sunni tribal groups and Sunni jihadists to fight a common enemy -- the government of Prime Minister Nouri al-Maliki -- are coming under strain. Those fissures are being watched closely as the U.S. military's Central Command is expected to deliver to the Pentagon this week a classified report on whether Iraq's shattered security forces can rally to combat the threat.
Exploiting any rifts among the Sunni militants is a top priority for U.S. and Iraqi officials and their regional allies.
The United States has weighed sending former U.S. officials to meet with Sunni tribal leaders. Ideally, the United States would try to recreate the Sunni Awakening alliances formed in 2007 that had nearly 100,000 Sunni tribal fighters to combat an earlier incarnation of ISIS. But these efforts are still very much in their infancy, officials said. At the same time, Saudi Arabia has reportedly urged Sunni tribes to turn against ISIS.
In developments elsewhere in the country, officials raised the death toll from Friday's suicide bombing in Kirkuk to 28 from 13.
As the military showdowns continued, the country's political parties were still attempting to form a new government after elections in April.