A car bomb killed at least nine people at a Shi'ite mosque in Baghdad Friday during mid-day prayers, and wounded at least 20. Violence continues even as U.S. officials say the insurgency appears to be weakening.

The attack in Baghdad on Friday came during the busiest time of the week at any mosque. Officials say the blast was so strong that it destroyed an empty bus parked outside the mosque, and caused the collapse of one of the building's walls. Witnesses say survivors carried out the wounded and dead by hand and wheel barrow. A broken water cistern left the floor covered by a mixture of water and blood.

This was the latest in a series of attacks on both Shi'ite and Sunni mosques, as violence in Iraq focuses more and more on Iraqi civilians and its new security forces.

Still, there are attacks on coalition troops and foreign civilians. On Friday, a U.S. soldier was killed by a roadside bomb in northern Iraq, and the U.S. military sent a team to help investigate the apparent downing of a civilian helicopter near Baghdad airport on Thursday, in which six Americans and five other foreigners were killed.

On Thursday and Friday, militant groups released videos of what they claim was the shooting down of the helicopter, and the execution of a survivor. The head of the Bulgarian company that owned the helicopter has confirmed that the man seen being shot to death in the execution video was one of the aircraft's pilots.

At the Pentagon, spokesman Lawrence Di Rita acknowledges that attacks have increased during the last two weeks, but he says attacks are down overall and it is not possible to say yet whether the last two weeks represent a new trend. "I would say that if you want to look at trends, I think the commanders feel that in terms of our ability to understand this enemy and interrupt the enemy, and the Iraqi security force's capacity against that enemy, is getting better all the time. The commanders wonder whether they're marshaling their dwindling capacity on being able to conduct these kinds of what appear to be better coordinated attacks, but more spectacular, and perhaps fewer more spectacular attacks. That's speculation," he said.

Meanwhile, the Arabic news channel al-Jazeera reports that the kidnappers of three Romanian journalists have given the Romanian government four days to withdraw its forces from Iraq, or the group says it will kill the reporters. The channel broadcast a videotape from the insurgents, showing the journalists, two men and a woman, and their translator, who reportedly has Romanian, Iraqi and U.S. citizenship. Romania has about 800 troops in the U.S.-led coalition, and public opinion in the country has been running against continuing the participation.