A US-Iraqi raid on the Abu Hanifa mosque -- one of the most revered sites for Sunni Muslims -- spawned a weekend of street battles, assassinations and a rash of bombings that changed Baghdad. The capital, for months a city of unrelenting but sporadic violence, has taken on the look of a battlefield.
The chaos has fanned sectarian tension and deepened Sunni distrust of interim Prime Minister Ayad Allawi, a Shiite installed by the Americans five months ago. It has also heightened the anxiety of the city's 6 million people -- already worn down by years of sanctions and tyranny, then war, military occupation, crime and deprivation.
"Baghdad is now a battlefield and we are in the middle of it," said Qasim al-Sabti, an artist who kept his children home from school Saturday, which is a work day in Iraq. When he sent his children back to school yesterday, the teachers didn't show up.
After sundown Sunday, four large explosions shook the area near Baghdad's US-guarded Green Zone -- a frequent target of insurgent mortars and rockets. There was no word on any damage or casualties.
In a sign of public unease, merchants in the outdoor markets, where most people buy their meat, vegetables and household supplies, say crowds are below normal. Many shops near sites of car bombings have closed.
Adding to the sense of unease, US military helicopters have begun flying lower over the city. The distant roar of jets has become a fixture of Baghdad at night.
The latest escalation appeared to have been triggered by a US-Iraqi raid Friday on the Abu Hanifa mosque in the Sunni neighborhood of Azamiyah as worshippers were leaving after midday prayers. Witnesses said three people were killed, and 40 were arrested.
The next day, heavy street fighting erupted in Azamiyah between US and Iraqi forces and Sunni insurgents who tried to storm a police station. The fighting, involving mortars, rocket propelled grenades and roadside bombs, raged for several hours and left several stores ablaze, according to witnesses.
Almost simultaneously, clashes broke out in at least five other Baghdad neighborhoods. In all, at least 10 people, including one American soldier, were killed throughout the capital Saturday.
Lieutenant Colonel James Hutton, spokesman for the US Army's 1st Cavalry Division, which is in charge of security in Baghdad, acknowledged that there has been an increase in insurgent activity in the capital.
But he linked the increase to the fighting in Fallujah, where US troops are still fighting pockets of resistance after recapturing the city last week, rather than the raid on the Abu Hanifa mosque.
The government has said the raid was carried out because of suspicions of "terrorist activity" there. It appears the operation was part of a crackdown on militant Sunni clerics, many of whom are believed to have links to some insurgent groups and who had spoken out against the Fallujah operation.
The Friday raid came at a time when sectarian tensions in Baghdad were already running high over the assault on the mainly Sunni Arab city of Fallujah. Baghdad's population is a potentially explosive mix of Sunnis, Shiites and Kurds. With frustration mounting over soaring crime, unemployment and poor services, Allawi can ill-afford to allow Baghdad to descend further into chaos.
The signs, however, are not encouraging. With the Jan. 30 national election now only two months away, the rivalry between various ethnic and religious groups is intensifying.