Palestinian police have arrested a leader of the Islamic Jihad militant group following a gun battle in Gaza city.

The arrest came on day of new violence as Israeli forces ringing Palestinian cities reportedly shot dead two people including a young boy.

Mohammed al-Hindi initially escaped scores of Palestinian policemen who came to arrest him at his home when a fierce gun battle erupted between the police and his supporters.

Mr al-Hindi, whose group has been responsible for recent attacks on Israeli targets, told the BBC that he had arrived at his home and found police trying to break down his door.

He escaped in a hail of bullets but, hours later, Palestinian security officials announced that he had been finally detained.

Shootings

Two Palestinians, including a young boy, are reported to have been shot dead in the West Bank town of Jenin on Saturday.

The shootings came as Israeli tanks moved right up to the entrance of Jenin, blocking all roads in and out.

The Israelis say operations at Jenin and Nablus are a response to the recent upsurge in violence which has seen seven Israelis and - including today's casualties - nine Palestinians killed since the start of a mission by US peace envoy Anthony Zinni.

In Jenin, a group of boys had gathered to throw stones at a tank when, according to Palestinians, troops opened fire, killing Mohammed Sahlah, 12.

Witnesses told Reuters news agency that troops opened fire killing 18-year-old Rami As'oos as he tried to pass the road blocked at the southern entrance to Jenin.

The Israeli army, which describes Jenin and Nablus as "terrorist hot spots", said it was checking the reports.

Peace mission

The Israeli deployment came after a suicide attack on Thursday by a member of Islamic Jihad, who blew himself and three Israelis up on a bus.

Israeli forces had only pulled out of Jenin last Tuesday as Mr Zinni met Israeli Prime Minister Ariel Sharon to discuss how to end 14 months of bloodshed.

The BBC's Caroline Hawley in Jerusalem says the army's return to Jenin will complicate Mr Zinni's mediation mission.

It also sets the scene for tough talking on Monday when Mr Sharon meets President Bush in Washington.

Mr Sharon says there must be one week of calm before he will negotiate

The US has criticised Israeli incursions into Palestinian-controlled territory.

But Washington has also, along with Israel, demanded that the Palestinian Authority arrest Islamic militants blamed for dozens of attacks on Israelis in recent years.

The Palestinian Authority has said it is working to stop attacks against Israeli civilians, and had ordered its security agencies bring perpetrators "to justice".

Mr Zinni was meeting Palestinian security chiefs during a tour of Gaza when the first attempt to arrest Mohammed al-Hindi was made on Saturday.

Mr Zinni said his priority was to restore calm.

"The most important thing to deal with initially is a sustained ceasefire," he said.