The Israeli occupation army killed 12 Palestinians, among them several children, in a controversial air strike on a Hamas activist leader and a foray into a Gaza town, and an extreme right-wing Jewish group claimed responsibility for a blast in a West Bank school that injured 29 Palestinian pupils. As the Palestinians slammed a late Tuesday Israeli air strike on Gaza City as a bid to "sabotage" an internationally backed peace "roadmap", German Foreign Minister Joschka Fischer pushed their leader Yasser Arafat to hurry reforms aimed at sharing power with his moderate new premier.

Israel defended the missile strike by an F-16 fighter-bomber and two Apache helicopters, which killed seven Palestinians, including three Hamas Islamists and four civilians.

Military sources said the raid targeted Hamas leader Saad al-Arabid, "responsable for attacks which killed and wounded dozens of people".

"Saad al-Arabid was a particularly dangerous terrorist," said Deputy Defence Minister Zeev Boim.

"We have not changed our policy on targeted operations against terrorists since the US intervention in Iraq ," he added.

Shortly after the F-16 strike, two Apache helicopters fired two missiles at the same area, witnesses said. That second attack raised the death toll and doubled the number of injured as it hit emergency service workers and onlookers staring at the wreckage from the first missile.

Women and children were among the 47 wounded, eight of whom were said to be in critical condition.

Hamas's armed wing, the Ezzedin al-Qassam Brigades, responded by firing a home-made missile from the Gaza Strip into the southern Israeli town of Sderot, without causing damage or injury.

And around Israeli 15 tanks rumbled into the town of Beit Hanun, just north of Gaza City, at dawn in a raid that left five Palestinians, including a 13-year-old boy, dead as the Israelis opened fire on crowds of stone-throwing youths.

At the same time, medics said a 12-year-old Palestinian boy who was injured in an Israeli raid on Jabalya refugee camp early last month died from his wounds.

Hamas again swore bitter vengeance, with political leader Abdul Aziz al-Rantissi saying the group would act "quickly" to avenge the six deaths.

The diplomatically isolated Arafat called the Gaza air raid "an unforgivable crime" after meeting in Ramallah, in the West Bank, with Fischer, his first meeting with such a senior foreign official in almost a year.

Chief Palestinian negotiator Saeb Erakat accused Israel of launching the attack to "sabotage" the push to implement the international peace "roadmap", which Israel wants to see heavily amended before being published.

"Israel is doing all it can to sabotage the roadmap with its policy of killing and destruction," he said. "The roadmap has been delayed more than six times."

The roadmap was drawn up by US, UN, EU and Russian diplomats to end the 30-month conflict and create an independent Palestinian state alongside a secure Israel by 2005.

US President George W. Bush has said he will publish the roadmap when new Palestinian prime minister Mahmud Abbas has formed his cabinet. On Wednesday, Arafat gave Abbas an extra two weeks to do so.

Fischer also met with Abbas, who is pushing for reforms and for an end to Palestinian attacks on Israelis.

One official in the German delegation said Fischer had told Arafat "that a real breakthrough in the dynamics of change is necessary."

Fischer had earlier met with Israeli leaders, stressing the need to support the moderate Palestinian premier as the latter struggled to form a government, mainly owing to disagreements with Arafat.

"The roadmap is an excellent proposal. The reforms in Palestinian areas must be supported," Fisher said in Jerusalem Tuesday.

Israel said it hoped that with the fall of Saddam Hussein's regime to US invasion forces in Iraq, the Palestinians would "draw the right conclusions."

"Now that the Iraqi people, thanks to America and Britain, are getting rid of their own brutal dictatorship, we hope that also our Palestinian neighbours will draw the right conclusions and give the necessary authority to a more peaceful leadership of their own", said Zalman Shoval, aide to Prime Minister Ariel Sharon .

Meanwhile, more violence erupted in the northern West Bank when a bomb ripped through a school in the village of Al-Jarba, south of Jenin.

A radical right-wing Jewish group on Wednesday claimed responsibility for the explosion that injured 29 Palestinian children, Israeli occupation army radio said.

The group, calling itself "Revenge of the Babies," said in a message sent to the radio that the blast was "to avenge the Jewish children killed by the Palestinians."

But Israeli security officials said they doubted the claim, and that they believed the bomb -- possibly explosives found in the village -- was taken into the school by a student.

PHOTO CAPTION

The brother of Palestinian Ahmad al-Ashram weeps as he blocks his ears during the funeral of his 12-year-old brother and six other Palestinians who were killed in an Israeli air strike on Gaza City(AFP/Mohammed Saber)