Baghdad, Iraq ? Two American soldiers were killed Saturday in Baghdad, seven Shiite construction workers were gunned down and five Sunni civilians were blown up, deepening the capital’s security crisis. Shiite politicians called on the prime minister to cancel his visit to Washington to protest Israel’s attacks in Lebanon.

One U.S. soldier died in the second of two roadside bombs that exploded in east Baghdad at mid-morning. An Iraqi civilian was killed by the first blast, police said. Another American soldier died Saturday evening when gunmen attacked his patrol with small arms fire, the military said.

The seven Shiite workers were killed and two were wounded when gunmen opened fire on a construction site near Baghdad International Airport, police said. Later Saturday, a mortar shell killed five civilians at a market in the mostly Sunni neighborhood of Amil in west Baghdad, police said.

The violence appeared to be part of the tit-for-tat reprisal killings by Sunni and Shiite extremists, which have led to a dramatic deterioration of security in the Iraqi capital.

Two rockets also blasted the heavily guarded Green Zone, which includes the U.S. and British embassies as well as major Iraqi government offices, but the U.S. military said there were no casualties.

U.S. troops also reported killing 15 gunmen in a three-hour firefight in Musayyib, 40 miles south of Baghdad.

With violence rising, the United States is moving to bolster American troop strength in the Baghdad area, putting on hold plans to draw down on the 127,000-member U.S. military mission in Iraq.