Three Israeli soldiers were killed overnight by friendly fire in the ongoing battle in the Hamas-ruled Gaza Strip, said the Israel Defense Forces (IDF) on Tuesday.

The biggest single death toll of the Israeli army since its Operation Cast Lead began 11 days ago came when an IDF tank shelled in error a structure where a unit of Israel's elite Golani Brigade were located, said the IDF in a statement.

"Three IDF soldiers were killed, one was critically wounded, three were severely wounded and 20 soldiers were lightly to moderately wounded as a result," said the statement, adding that the incident happened "during an operation in northern Gaza Strip".

Golani Brigade commander, Colonel Avi Peled, who oversaw the evacuation in the field and directed the artillery and aerial cover, sustained light injuries in the incident, according to the IDF.

The friendly fire incident increased the overall death toll on the Israeli side to eight, including four civilians. Half of them died in rocket attacks by Gaza militants before the IDF launched the ground offensive on Saturday night, and the other four were killed in the ground battle.

Israeli troops have been engaged in fierce fighting with Gaza militants as they move into the densely populated urban area in the coastal Palestinian enclave, where over 540 have been killed and some 2,500 others injured.

Brushing away mounting pressure from the international community, Israeli leaders said Monday that the assault will continue until the goal of restoring security to southern Israel is realized.

(Xinhua News Agency January 6, 2009)