U.S. to Review Green Zone Security

Deadly bombings in Baghdad's Green Zone (search) have touched off a U.S. security review and a search for evidence to determine if terrorists linked to Abu Musab al-Zarqawi (search) carried out the attacks.

Two bombers penetrated the tightly guarded area of the Iraqi capital and struck at a bazaar close to the U.S. Embassy annex and at a cafe. Witnesses said both carried backpacks and spent considerable time sipping tea in a cafe before striking.

Four employees of the private U.S. security firm DynCorp (search) were killed and a fifth wounded. Three State Department workers were injured. At least six Iraqis died.

Condemning the bombings and extending sympathies to the families of the victims, State Department spokesman Richard Boucher said Thursday, "Our people who go out (to Iraq) know that they are serving in dangerous circumstances."

But, he said, "It's obviously very sad and unfortunate when something happens to them or to the Iraqis who are working with them in the Green Zone and elsewhere in the country."

Americans and Iraqis working at the embassy were instructed to remain inside the complex indefinitely. Boucher said an investigation and security sweeps were under way.

Two other U.S. officials said the contract workers were from DynCorp, which assists in trying to protect U.S. facilities. Mike Dickerson, a spokesman for Computer Services Corp. (search), DynCorp's parent company, said three employees had been killed and a fourth was missing. Their identities were not being released pending notification of their families.

Security arrangements were put under immediate review. Boucher said it is "much too early to start speculating" about possible changes.

"Every time there is an incident like this we automatically look for what we can do to improve security for everybody who lives and works in these areas," Boucher said.

Tawhid and Jihad (search), al-Zarqawi's militant group, claimed responsibility for the blasts.

It was the first time a bomb was set off within the Green Zone. In the past, there have been rocket attacks from beyond the perimeter. Also, an explosive device was found in the zone recently.

Secretary of State Colin Powell, in a speech Wednesday night in Washington, spoke of "facing a difficult time in Iraq" while expressing confidence that the U.S.-led coalition gradually would gain the upper hand.