Militants target Palestinian officials

The PFLP has demanded Saadat's release

Palestinian militants have threatened to harm leading members of the Palestinian Authority unless the detained head of the radical Popular Front for the Liberation of Palestine (PFPL) is freed.

The military wing of the PFLP - the Martyr Abu Ali Mustafa Brigades - issued a statement denouncing the arrest by Palestinian police of Ahmad Saadat, saying the Palestinian Authority had caved in to Israel's demands.

Our hand will reach [Palestinian security officials] whatever guards they may have

Martyr Abu Ali Mustafa Brigades

Mr Saadat was detained on Monday night after being lured to a meeting with Palestinian Authority officials, according to the PFLP.

Israel had insisted that the Palestinians arrest Mr Saadat, whom its says was behind the assassination of an Israeli minister last October, as a condition for allowing Palestinian leader Yasser Arafat to leave his encircled Ramallah HQ in the West Bank.

In its statement, the PFLP Brigades said: "We warn the Palestinian Authority's security leaders, especially Tawfiq al-Tirawi, head of West Bank intelligence, and Ramallah police chief Mohammed Saleh, to stop arresting our members and leaders, otherwise our hand will reach them whatever guards they may have."

Israel says Saadat ordered the assassination of its tourism minister

The PFLP's political leadership has distanced itself from the statement, which correspondents say marks the first time Palestinian militants have directly threatened Palestinian officials since the Palestinian intifada, or uprising, broke out in September 2000.

Mr Arafat has taken restrictive steps against radical Palestinian groups after coming under intense Israeli and international pressure following a spate of suicide bombings in Israel in early December.

The Brigades said Mr Saadat's detention was a "submission to Israeli and American dictates".

On Wednesday, Palestinian militants meeting in Damascus called Mr Saadat's detention "a very dangerous political development in which the Palestinian Authority takes all the responsibility".

Israeli scepticism

The Palestinian leadership has resisted staging a full-scale crackdown on militants, fearing an internal backlash.

The main militant groups rivalling Mr Arafat - Hamas and Islamic Jihad - have recently threatened to resume attacks against Israel, despite a call by the Palestinian leader to respect a ceasefire.

Israel has voiced scepticism over the Palestinians' claim to have arrested Mr Saadat.

Israeli Prime Minister Ariel Sharon told reporters: "We have not seen any arrests whatsoever. There were no serious arrests."

Israel says Mr Saadat ordered the killing of its Tourism Minister Rehavam Zeevi and that he and the two assassins have been sheltering in Ramallah since the murder on 17 October, 2001.