Roadside bombs killed seven American troops in Iraq on Saturday, including four in a single strike outside Baghdad, the military said, as U.S. and Iraqi troops captured two senior Al Qaeda militants in Diyala province.

Separately, a predawn operation by U.S. forces working with Iraqi informants in Baghdad's main Shiite district of Sadr City netted three other militants suspected of ties to Iran, the military said.

The Americans have accused Iran of providing mainly Shiite militias with training and powerful roadside bombs known as explosively formed projectiles, or EFPs, that have killed hundreds of U.S. troops in recent months.

Roadside bombs, including EFPs and other makeshift devices used by Sunni and Shiite militants alike, are the No. 1 killer of foreign troops in Iraq and Saturday's deaths were no exception.

Roadside bombs killed four soldiers northwest of the capital, a U.S. airman in Tikrit, and two U.S. soldiers in eastern Baghdad whose unit has recently targeted bomb networks. In addition, a British soldier died Saturday of wounds from a roadside bombing the day before in the southern city of Basra.

The announcement of the capture of two senior Al Qaeda members in Diyala province came after concerns were raised that much of the terror organization's local leadership fled before a major U.S. military crackdown began on Monday.

The U.S. ground forces commander, Lt. Gen. Raymond Odierno, has said Baqouba's Al Qaeda leadership learned about the American advance beforehand and fled before the Americans moved in.

Iraqi Maj. Gen. Abdul Karim al-Rubaie said the suspects were transferred to Baghdad, but he provided no more information about their identities. Seven other suspected Al Qaeda fighters were arrested in the center of Baqouba, and 30 hostages were released from a prison elsewhere in the provincial capital, al-Rubaie said.

The U.S. military said earlier Saturday that at least 55 Al Qaeda operatives have been killed and 23 detained since the start of Operation Arrowhead Ripper. It also said 16 weapons caches have been discovered, and 28 roadside bombs and 12 booby-trapped structures have been destroyed.

Earlier this week, creeping house-to-house through western Baqouba, U.S. soldiers made a startling discovery: a suspected Al Qaeda field hospital stocked with oxygen tanks, heart defibrillators and other medical equipment.

The find displayed Al Qaeda's sophisticated support network in Baqouba, a mostly Sunni city of about 300,000 people.

Baqouba has received little aid or other services from the central government, which feared supplies would end up with Al Qaeda. As the field hospital proved, much assistance did end up bypassing residents and found its way to the terrorist organization.

"There are a multitude of systematic functions that aren't working," said Maj. Robbie Parke, 36, spokesman for the 3rd Brigade, 2nd Infantry Division. "The Iraqi government has to say, `Look, Baqouba is in trouble, and we need to help."'

So far that has not happened, U.S. officials say. But there are signs of hope.

"The (Iraqi) government is very immature, but they're getting better and saying the right things. We've got to hold them to that," said Odierno, the ground forces commander.

He spoke to AP during a trip to Baqouba on Thursday as American forces began in earnest to squeeze Al Qaeda, Sunni insurgents and Shiite militiamen after the arrival of the final brigade of an additional 30,000 troops dispatched by President Bush.