UN contractors killed in Iraq

Two foreign contractors working for the UN have been killed and 15 wounded in a rocket attack on Baghdad's high-security Green Zone, the UN says.

The Green Zone houses government offices and many foreign embassies.

It is not known who carried out the attack, which comes just days after the Iraqi parliament approved a new security pact with the United States.

The victims worked for a catering company contracted by the UN Assistance Mission for Iraq, officials say.

There have been many such attacks in the past, but they stopped after a ceasefire earlier this year between the Iraqi government and supporters of the anti-American Shia cleric Moqtada Sadr, says the BBC's Humphrey Hawksley in Baghdad.

On Thursday, the Iraqi parliament voted in favour of a new security pact with the United States, under which American troops are to leave Iraq by the end of 2011.

Moqtada Sadr condemned the agreement and called for three days of protests against the plan, but he specified they should be peaceful.

Levels of violence in Iraq have fallen to a four-year low, but bombings continue on an almost daily basis.

The UN's presence in Iraq has been limited since a suicide bombing of its Baghdad headquarters in 2003 killed 22 people, including its top envoy, Sergio Vieira de Mello.