‘I ask the Iraqi resistance to engage in revenge operations against the United States, the biggest parter of the Zionist enemy,’  Sadr said in a statement issued by his office in the central shrine city of Najaf.

He called on ‘all countries which host Israeli embassies on their territory to close down those missions which are the source of terrorism in Arab and Islamic countries as a sign of support for the Palestinian people.’

He called on Iraqis to ‘place Palestinian flags on the roofs of all buildings, mosques and churches in a show of support for the mujahedeen (holy warriors) in Gaza.

Sadr’s movement, which draws broad support from poorer Shias and dominates the vast Baghdad slum district of Sadr City, has long been a staunch opponent of the US-led military presence in Iraq.

Its bloc in parliament campaigned strongly against last year’s bilateral security deal with Washington which paved the way for US troops to stay on Iraq until 2011 after a UN mandate expired on December 31.

Sadr had stood down his movement’s long feared Mahdi Army militia in August 2007 but his aides said a smaller leaner fighting force would be retained.

At least 689 people, including 220 children, have been killed since Israel launched Operation Cast Lead against Gaza on December 27.

Washington has expressed strong backing for the operation saying it was Israel’s right to defend itself against rocket and mortar fire by Gaza militants. It has opposed all moves at the UN Security Council to adopt an Arab draft resolution demanding an immediate ceasefire.