U.S. raises security alert in Green Zone, 20 said detained in foiled bombing; two American soldiers killed

BAGHDAD, Iraq — Two American soldiers were killed and two others were wounded in separate attacks involving roadside bombs, U.S. officials said Thursday, and 20 Iraqis were arrested in the north in operations against those suspected of planting explosives.

U.S. authorities, meanwhile, raised the security alert in the heavily guarded Green Zone after an improvised bomb was found in front of a restaurant there.

One U.S. soldier from the 13th Corps Support Command died when a bomb exploded near his convoy late Wednesday outside the insurgent stronghold of Fallujah, the command said. Two other soldiers were wounded.

A 1st Infantry Division soldier was killed and an Iraqi interpreter wounded when insurgents attacked a patrol with a roadside bomb near Beiji, 155 miles north of Baghdad, the command said.

Four U.S. Marines and three Iraqi soldiers were injured this week in an operation to crush insurgents south of Baghdad.

About 240 detainees, meanwhile, were released from U.S. and Iraqi custody Thursday — including a prominent supporter of radical cleric Muqtada al-Sadr, the U.S. military said. It was the fourth round of releases under a joint U.S.-Iraqi review process set up Aug. 21 following the prisoner abuse scandal at Abu Ghraib prison in a continuing effort to reduce the inmate population and free those deemed not to be a security threat.

The publication in April of photographs showing naked, terrified Iraqi prisoners being abused and humiliated by grinning American guards at Abu Ghraib caused outrage here and internationally.

None of those freed Thursday were "high-value" detainees, who are processed separately from the 1,700 "security detainees" held at the Abu Ghraib facility near Baghdad and Camp Bucca in southern Iraq, said Lt. Col. Barry Johnson, a military spokesman.

About 830 detainees have been released in all since the Combined Review and Release Board began reviewing files in August. The military aims to transfer the bulk of the remaining Abu Ghraib security detainees to Camp Bucca, which currently is being expanded and upgraded to become the primary holding facility at the start of next year, Johnson said.

The warning to Americans and Iraqi officials in the Green Zone followed the discovery Tuesday of an explosive device at the Green Zone Cafe, a popular hangout for Westerners living and working in the compound — which houses major U.S. and Iraqi government offices. A U.S. military ordnance detachment safely disarmed it, U.S. officials said.