Palestinian President Mahmoud Abbas' Fatah Party has confirmed the death of Ziad Abu Ain, a minister responsible for dealing with Israeli settlements and the West Bank security barrier.

Witnesses say the clashes began on Wednesday when dozens of Palestinians, including Abu Ain, 55, headed to agricultural land near the village of Turmus Aya to plant olive tree saplings on fields belonging to Palestian villagers but mostly off limits. The area is close to an Israeli settlers' outpost.

Mahmoud Aloul, Fatah's senior member, told the news agency Associated Press that as the Palestinians marched towards the farmland, Israeli security forces tried to stop them and fired tear gas. He said a gas canister hit the minister, a claim which could not be verified.

Hit in the chest, says marcher

Some sources also said that Abu Ain got involved in a scuffle with an Israeli soldier. Salah Hawajeh, a marcher, claimed that an Israeli officer head-butted Abu Ain and then hit him in the chest with his rifle.

The Palestinian minister lost consciousness and was taken to hospital where he died of heart failure, said Fatah official Qadoura Faris.

The Israeli army said it was investigating the fatal incident.

Osama Najar, a Palestinian health ministry spokesman, said an autopsy would be carried out to determine the exact cause of the minister's death.

The Palestinian Authority said it was weighing its response.

Abu Ain had previously served as deputy minister for prisoner affairs.

shs/ipj (AP, dpa)