Gunmen shot dead two protesters in Iraq's southern city of Nassiriya overnight and a Baghdad district became a battlefield on the third day of a drive by security forces to end months of demonstrations against the largely Iran-backed ruling elite.

Clashes over the weekend had already killed at least five protesters. Rockets also hit the U.S. Embassy compound in Baghdad's fortified Green Zone housing government buildings.

Ambassadors of 16 countries in Baghdad, including the U.S., France and Britain, condemned the use of live fire by Iraqi security forces and called for a credible investigation into the deaths of more than 500 protesters since October.