Gaza-fired rocket hits near Tel Aviv

A rocket fired from the Gaza Strip landed close to Tel Aviv today, in the first attack on Israel's biggest city in 20 years, raising the stakes in a military showdown between Israel and the Palestinians that is moving towards all-out war.

Earlier, a Hamas rocket killed three Israelis north of the Gaza Strip, drawing the first blood from Israel as the Palestinian death toll rose to 15.

On the second day of an assault that Israel said might last many days and culminate in a ground attack, its warplanes bombed targets in and around Gaza city, shaking tall buildings.

Plumes of smoke and dust furled into a sky laced with the vapour trails of outgoing rockets over the crowded city, where four young children killed yesterday were buried.

The sudden conflict, launched by Israel with the killing of Hamas's military chief, pours oil on the fire of a Middle East already ablaze with two years of revolution and an out-of-control civil war in Syria.

Egypt's new Islamist president Mohamed Mursi, viewed by Hamas as a protector, led a chorus of denunciation of the Israeli strikes by Palestinian allies.

Mr Mursi's prime minister, Hisham Kandil, will visit Gaza tomorrow with other Egyptian officials in a show of support for the enclave, an Egyptian cabinet official said. Israel promised that the delegation would come to no harm.

Israel says its attack is in response to escalating missile strikes from Gaza. Israel's bombing has not yet reached the saturation level seen before it last invaded Gaza in 2008, but Israeli officials have said a ground assault is still an option.

Israeli police said three Israelis died when a rocket hit a four-story building in the town of Kiryat Malachi, some 25km north of Gaza, the first Israeli fatalities of the latest conflict to hit the coastal region.

Air raid sirens sent residents running for shelter in Tel Aviv, Israel's commercial centre which has not been hit by a rocket since the 1991 Gulf War. A security source said it landed in the sea. Tel Aviv residents said an explosion could be heard.

The Tel Aviv metropolitan area holds more than three million people, more than 40 per cent of Israel's population.

Israeli prime minister Benjamin Netanyahu said Hamas was committing a double war crime, by firing at Israeli civilians and hiding behind Palestinians civilians.

"I hope that Hamas and the other terrorist organisations in Gaza got the message," he said. "If not, Israel is prepared to take whatever action is necessary to defend our people."

Hamas spokesman Fawzi Barhoum said Israel would pay a heavy price "for this open war which they initiated".

After watching powerlessly from the sidelines of the Arab Spring, Israel has been thrust to the centre of a volatile new world in which Islamist Hamas hopes that Mr Mursi and his newly dominant Muslim Brotherhood in Egypt will be its protectors.