Massive Israeli air raids on Gaza

Israeli F-16 bombers have pounded key targets across the Gaza Strip, killing more than 200 people, local medics say.

Most of those killed were policemen in the Hamas militant movement, which controls Gaza, but women and children also died, the Gaza officials said.

About 700 others were wounded, as missiles struck security compounds and militant bases, the officials said.

Israel said it was responding to an escalation in rocket attacks from Gaza and would bomb "as long as necessary".

They were the heaviest Israeli attacks on Gaza for decades. More air raids were launched as night fell.

The operation came days after a truce with Hamas expired.

Israeli Defence Minister Ehud Barak said "it won't be easy and it won't be short".

"There is a time for calm and a time for fighting, and now the time has come to fight," he said.

US Secretary of State Condoleezza Rice accused Hamas of having triggered the new bout of violence.

"The United States strongly condemns the repeated rocket and mortar attacks against Israel and holds Hamas responsible for breaking the ceasefire and for the renewal of violence in Gaza," she said.

"The ceasefire should be restored immediately. The United States calls on all concerned to address the urgent humanitarian needs of the innocent people of Gaza."

UN Secretary-General Ban Ki-moon also urged an immediate halt to the violence, condemning what he called Israel's "excessive use of force leading to the killing and injuring of civilians" and "the ongoing rocket attacks by Palestinian militants".

Calls for a ceasefire also came from Middle East envoy Tony Blair and the French EU presidency.

Palestinian militants frequently fire rockets against Israeli towns from inside the Gaza Strip; large numbers of rocket and mortar shells have been fired at Israel in recent days.

In a statement, Israel's military said it targeted "Hamas terror operatives" as well as training camps and weapons storage warehouses.

Hamas bases destroyed

A Hamas police spokesman, Islam Shahwan, said one of the raids targeted a police compound in Gaza City where a graduation ceremony for new personnel was taking place.

Hamas will continue the resistance until the last drop of blood Fawzi Barhoum Hamas spokesman

At least a dozen bodies of men in black uniforms were photographed at the Hamas police headquarters in Gaza City.

Israel said operations "will continue, will be expanded, and will deepen if necessary".

It is the worst attack in Gaza since 1967 in terms of the number of Palestinian casualties, a senior analyst told.

Israeli Foreign Minister Tzipi Livni defended the air raids, saying Israel had "no choice". "We're doing what we need to do to defend our citizens," she said in a television broadcast.

Israel hit targets across Gaza, striking in the territory's main population centres, including Gaza City in the north and the southern towns of Khan Younis and Rafah.

Hamas said all of its security compounds in Gaza were destroyed by the air strikes, which Israel said hit some 40 targets.

Mosques issued urgent appeals for people to donate blood and Hamas sources told that hospitals were soon full.

In the West Bank, Palestinian Authority President Mahmoud Abbas - whose Fatah faction was ousted from Gaza by Hamas in 2007 - condemned the attacks and called for restraint.

Civilians were caught up in the air strikes in heavily-populated Gaza

But Hamas quickly vowed to carry out revenge attacks on Israel in response to the air strikes, firing Qassam rockets into Israeli territory as an immediate reply.

One Israeli was killed by a rocket strike on the town of Netivot, 20 kilometres (12 miles) east of Gaza, doctors said.

"Hamas will continue the resistance until the last drop of blood," spokesman Fawzi Barhoum was reported as saying.

The air strikes come amid rumours that an Israeli ground operation is imminent.

Israeli television said on Saturday evening that Israeli troops were massing on the Gaza border "in preparation for a supplementary ground offensive". The report has not been confirmed by independent sources.

Israel's Haaretz newspaper reported that about 60 warplanes took part in the first wave of air strikes.

Most of the dead and injured were said to be in Gaza City, where Hamas's main security compound was destroyed. The head of Gaza's police forces, Tawfik Jaber, was reportedly among those killed.

Residents spoke of children heading to and from school at the time of the attacks.

Egypt opened its border crossing to the Gaza Strip at Rafah to absorb and treat some of those injured in the south of the territory.

Palestinians staged demonstrations in the West Bank cities of Ramallah and Hebron, and there were some scuffles with Israeli troops there.

Although a six-month truce between Hamas and Israel was agreed earlier this year, it was regularly under strain and was allowed to lapse when it expired this month.

Hamas blamed Israel for the end of the ceasefire, saying it had not respected its terms, including the lifting of the blockade under which little more than humanitarian aid has been allowed into Gaza.

Israel said it initially began a staged easing of the blockade, but this was halted when Hamas failed to fulfil what Israel says were agreed conditions, including ending all rocket fire and halting weapons smuggling.

Israel says the blockade - in place since Hamas took control of Gaza in June 2007 - is needed to isolate Hamas and stop it and other militants from firing rockets across the border at Israeli towns.