LONDON (AFP) – Britain renewed its call on Monday for a ceasefire between Israel and Palestinian militants, while lamenting the "unacceptable" loss of innocent lives as Israeli strikes in Gaza continued for a third day.

Foreign Secretary David Miliband warned the region was facing a "dangerous and dark moment".

Asked if the Israeli attacks could be justified, Miliband told BBC radio: "I think that any innocent loss of life is unacceptable and in this case there have been massive casualties, some of them civilians and some of them children.

"That is one reason we have called for a ceasefire.

"This is a very dangerous and very dark moment, partly because of the lives that have been lost and the humanitarian crisis that exists; partly because of the threat to the chance of the comprehensive peace that is so important for the Palestinians,

"But also for Israel; and partly for the fuel for radicalism that can be argued by some to be the right response," he added.

The comments came as Israeli jets bombed Hamas targets in Gaza for a third day, killing several children, while the Islamists fired deadly rockets in retaliation for the deadly raids which have left more than 300 dead.

As Israeli tanks massed on the Gaza border, the army declared the area a closed military zone -- a move that in the past has often been followed by ground operations in the Palestinian enclave.

The Israeli blitz, unleashed on Saturday in retaliation for ongoing rocket and mortar fire from Gaza, has killed at least 312 Palestinians and wounded more than 1,400 others, according to Gaza medics.

Miliband added: "There is no point in me denying my fear that this will fuel radicalism ... That is one of the dangers we face at the moment.

"I think it is incumbent on us to argue very strongly for a ceasefire that does protect Israel but also, critically, we have to ensure that the authority of the Palestinian Authority and President (Mahmud) Abbas is reinforced."