A Palestinian suicide bomber has blown himself up in northern Israel after being challenged by Israeli soldiers.

No-one else was hurt in the attack which came as Israel continued building a controversial new security fence to try to stop Palestinian militants crossing into its territory.

The suicide attack occurred near the Arab-Israeli village of Kafr Salem, where work on the fence started on Sunday.

The fence is the latest effort by Prime Minister Ariel Sharon to halt the wave of suicide attacks in Israeli cities and towns.

The move has angered Palestinians, who accuse Israel of seizing more of their land, and also Jewish settlers who oppose any boundary between Israel and territory it occupied in the 1967 war.

But Amos Yaron of the Israeli Defence Ministry said the fence "will provide a defensive answer to the... infiltration of terrorists".

Suicide bombings have killed scores of Israelis since a Palestinian uprising against Israeli occupation began in September 2000 after peace talks stalled.

The Israeli army pulled out of the Palestinian-controlled town of Jenin on Sunday after a brief raid, Israeli radio reported.

Palestinian security sources earlier reported that around 30 tanks and armoured vehicles had rolled into the city. Local residents reported hearing shots, they said, without being able to say if there had been any casualties.

Few details of its exact route of the fence have been revealed.

Israeli support

The first phase of the plan is reported to involve 110 kilometres (70 miles) of trenches and electric fencing separating the towns of Jenin, Tulkarm and Qalqilya from Israeli cities.

Jenin, a stronghold of Palestinian militants, is where the Israeli army says more than 20 suicide bombers have come from over the past 20 months of renewed conflict.

Reports say the fence will be electrified and will have devices to detect any movement on it.

Such fences are already used in the Gaza strip to protect settlements near to Palestinian population centres.

Opinion polls show at least 80% of Israelis are in favour of the fence.

In the US, President George W Bush and his policy advisers are continuing to work on a new statement to halt the violence in the region, which is expected to be unveiled this week.

The White House has acknowledged Mr Bush is mulling the creation of a provisional state to exist alongside Israel.