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 here 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.