Washington ? The top U.S. commander in Iraq said Friday that “the crisis has passed” after an outbreak of sectarian fighting 10 days ago that left hundreds of Iraqi civilians dead, but he warned that violence could erupt again and that civil war, while unlikely, remains possible.

Army Gen. George Casey, the top U.S. military commander in Iraq, said he would take into account the Iraqi government’s reaction to the violence as well as the role of sectarian militias when he assesses this spring how many U.S. troops are needed in Iraq. Since December’s elections, the Pentagon has lowered force levels by more than 20,000, to about 133,000.

Casey pointed in particular to the need for Iraq’s government to “deal with the militia issue in the very near future,” saying that disarming the groups of sectarian fighters is vital to U.S. success in the long run.

“I do not believe that we will ultimately succeed until the Iraqi security forces, the police and the military, are the only ones in Iraq with guns,” he said during a Pentagon news briefing via teleconference from Iraq.

Overall, Casey portrayed an Iraq that remains fragile and uncertain, but in which the government and security forces are proving effective in containing the unrest and restoring calm.

“Is the violence out of control? Clearly not. Now, it appears that the crisis has passed,” he said.

Casey said that in the initial days after the Feb. 22 bombing of a sacred Shiite shrine in Samarra, there was “a confusing jumble of exaggerated reporting that actually took us a few days to, kind of, sort through.”

He said 350 Iraqi civilians had died in a surge of sectarian killings, militia violence and revenge attacks on about 30 mosques across the country after the bombing. “This, obviously, is unacceptable,” he said.

The Washington Post reported earlier this week that the death count was higher, quoting Baghdad morgue officials as saying it was more than 1,300 and, subsequently, an Interior Ministry official who put the number at 1,077.

An international official in Baghdad, speaking on the condition of anonymity, said about 1,000 people had been killed between the day of the bombing and Monday, and said the figure came from morgue officials and others. He said those officials have since acceded to a lower official count because they feared reprisals if they did not.

Casey said Iraqi security forces had taken the initiative and had performed “generally well” in response to the violence, with support from the United States and other coalition members. But he said there were exceptions, notably in Baghdad and Basra, when the Iraqi army and police took several days to quell the unrest.

Casey said he thought, but had no “conclusive evidence,” that an organization linked to al-Qaida carried out the attack on the domed mosque in Samarra. He said Iraqi forces are bolstering security at key religious sites amid reports that another major strike could be planned.

“Iraq is not out of danger. There is still a terrorist threat here that is working to foment continued sectarian violence,” he said.

Better security on Iraq’s borders has reduced the number of foreign fighters entering Iraq, Casey said – contributing to a decline in suicide bombings from 60 or 70 a month last summer to about 30 last fall and 17 in February.