BAGHDAD - A rocket landed in Baghdad's heavily fortified international Green Zone on Monday, rocking the US embassy but causing no casualties, witnesses said.

An Iraqi soldier stands by a car bomb wreck in front of a monument to Marouf al-Risafi, Iraqi poet, in central Baghdad, Iraq, Monday, March 26, 2007. Two people were killed and four were wounded in the bombing. [AP]

US embassy spokesman Lou Fintor would not say exactly where the rocket landed for security reasons but confirmed it had crashed into the sprawling international zone, which also houses the Iraqi government and other foreign embassies.

"Preliminary reports indicate the source of the explosion was a rocket. There were no casualties and minimal damage," he said.

A rocket landed close to a building where UN Secretary General Ban Ki-moon and Iraqi Prime Minister Nuri al-Maliki were holding a news conference in the Green Zone last week.

Monday's blast took place just hours after outgoing US ambassador Zalmay Khalilzad told reporters that he was cautiously optimistic about the future in Iraq.