Mortars hit Baghdad Green Zone during Biden visit

Militants fired several mortars or rockets at Baghdad's fortified Green Zone government district on Tuesday shortly after US Vice President Joe Biden flew in, underlining the fragility of Iraq's security gains.

Iraqi police said one mortar round killed two Iraqi civilians and wounded five when it blasted an apartment block in the zone. Another two rounds landed near the sprawling US embassy compound, but did not hit it.

Police had no further reports of casualties.

Biden had met with the US ambassador, Chris Hill, and the senior US military commander, General Ray Odierno, just before the mortar strikes. He was safe in an undisclosed location, aides said, his whereabouts kept secret for security reasons.

A briefing for journalists by Hill and Odierno was interrupted by the sound of explosions. A loudspeaker at the embassy broadcast a warning to duck and take cover.

The US military said it knew of only one blast from incoming fire, which hit near the Green Zone but not inside it.

It was Biden's second trip to Iraq in three months, and the visit signaled that the Obama administration is anxious to resolve long-standing disputes between Kurdish, Shi'ite and Sunni Arab communities over land and oil that US officials fear could yet rip apart the country.

After his meeting with Hill and Odierno, Biden said a national election in January was the key to resolving those differences, which have in recent weeks been on display through public quarrelling over who was to blame for bomb attacks.

"I think a successful election is the necessary condition for those outstanding political questions to be resolved ... most of the parties ... feel the same way," Biden said.

Violence has dropped sharply in Iraq since the height of a wave of sectarian killings in 2006, due in part to a so-called "surge" of tens of thousands of U.S. troops, but the security gains have not been matched by much political progress.

"I don't think necessarily the result of a failed political process is civil war," Hill said. "The threat is the political process will not give the country sufficient cohesion to work on its economic issues and otherwise to become a strong and stable factor in the region."