Hamas movement threatened to execute an Israeli captive every time Israel bombs a Palestinian home without warning, as Israel called up an unprecedented 300,000 reservists and imposed a blockade on the Gaza Strip, raising fears it planned a ground assault.
The violence, which has claimed more than 1,500 lives, prompted international declarations of support for Israel after a devastating weekend attack by Hamas, and appeals for an end to the fighting and protection of civilians.
Israeli TV channels said the death toll from the Hamas attack had climbed to 900 Israelis, with at least 2,600 injured, and dozens taken captive. Among the Israeli dead were 260 mostly young people gunned down at a desert music festival, where some of the hostages were abducted.
Israeli Prime Minister Benjamin Netanyahu vowed revenge in a fiery speech accusing Hamas of executing tied-up children and other atrocities.
«This vile enemy wanted war and it will get war,» he said.
Gaza's Health Ministry said at least 687 Palestinians had been killed and 3,726 wounded in Israeli air strikes on the blockaded enclave since Saturday. Apartment blocks, a mosque and hospitals were among the sites attacked, and the strikes destroyed some roads and houses, according to media reports and eyewitnesses.
Israel also bombed the headquarters of the private Palestinian Telecommunication Co., which could affect landline telephone, internet and mobile phone services.
The strikes continued into the night on Monday.