Dhaka, May 17 -- United Nations relief chief Tom Fletcher on Tuesday called on the UN Security Council to take action "to prevent genocide" in Gaza, delivering a scathing account of Israel's actions in the Palestinian territory.Fletcher, the UN Under-Secretary-General for Humanitarian Affairs, demanded that Israel lift its aid blockade on Gaza, where its offensive has killed tens of thousands and reduced much of the enclave to rubble."For those killed and those whose voices are silenced: what more evidence do you need now?" asked Fletcher. "Will you act - decisively - to prevent genocide and to ensure respect for international humanitarian law?"He alleged that Israel was "deliberately and unashamedly imposing inhumane conditions on civili...