Ramallah: Palestinian lawmakers probing the death in custody of a preacher from the Islamist Hamas movement said on Thursday he had been "tortured to death" by security men loyal to President Mahmoud Abbas.

A self-appointed investigation team comprising six independent lawmakers determined that Majd al-Barghouthi died as a result of torture and said the head of the Fatah-run intelligence services, Tawfiq Tirawi, should be held to account.

Another commission which Abbas appointed in late February to investigate the matter has not yet delivered its verdict, although a pathologist working on behalf of Fatah said he had not found signs of torture.

Independent lawmaker Hassan Khreisheh, a member of the investigating commission, said it had observed "torture marks" on the legs, back and arms of the 45-year-old father of nine, who had been detained for a week before his death.

He said witnesses had told the commission that Barghouthi had been tortured in a "mad manner".

Khreisheh said the lawmakers had demanded that Abbas punish anyone who participated in the torture of Barghouthi.

Tension between Hamas and Fatah has increased since the Islamists took control of the Gaza Strip in a brief but bloody civil war in June. Fatah still holds sway in the Israeli-occupied West Bank.

Ramallah (Reuters) A Palestinian public sector trade union on Friday threatened an "uprising" against Prime Minister Salam Fayyad's government after he said he would dock workers' pay if they expand current strike action.

The strike highlights tension between Fayyad, a former World Bank economist and political independent, and elements of the long-dominant Fatah movement led by Pres Mahmoud Abbas. Abbas appointed Fayyad last year after Islamist militants loyal to the former Hamas-led government took over the Gaza Strip.

"This is a political strike," said one independent minister in Fayyad's cabinet. "Some Fatah members have been putting continuous pressure on Abbas to bring Fatah into government."

Union leaders, many themselves Fatah members, denied any political intent.

Fayyad, who is resisting higher wage claims from civil servants, said his administration would dock pay from workers for each day they strike.

Union leader Bassam Zakarneh said Fayyad's move was illegal and that workers would resist the threat. "Fayyad is pushing us towards an uprising against his policies," he said.