A crisis has erupted between Hamas and Islamic Jihad following allegations that Hamas's security forces in Gaza have been trying to prevent rocket attacks on Israel.

The latest strife coincides with the start of reconciliation talks in Cairo between Hamas and Fatah. The latest round of negotiations, which began on Tuesday under the auspices of the Egyptian government, will last for 10 days and are aimed at reaching agreement on the formation of a Hamas-Fatah government.

On the eve of the talks, Hamas announced that more than 400 of its supporters were being held in prisons belonging to Palestinian Authority security forces in the West Bank.

Hamas called on PA President Mahmoud Abbas to release all the detainees, who are being held without trial, to ensure the success of the reconciliation talks in Cairo.

At least 10 Islamic Jihad members have been arrested in the past few days by Hamas's Internal Security Apparatus on charges of firing rockets at Israel, according to two Palestinian journalists in the Gaza Strip.

The journalists quoted Islamic Jihad officials as saying that some of the detainees were tortured while being held in a Hamas security installation in Khan Yunis.

The Islamic Jihad men were released after signing documents pledging to refrain from firing rockets at Israel, the journalists said. One Islamic Jihad man who refused to sign the pledge remained in prison, they added.

The latest rocket attacks came after Israel assassinated Khaled Sha'lan, a senior Islamic Jihad operative, in the Gaza Strip last week.

Sha'lan had been involved in firing rockets at Ashkelon.

Earlier, sources in the Gaza Strip reported that Hamas's security forces had arrested two members of a group called Palestinian Hizbullah, also on suspicion of firing rockets at Israel.

A Hamas official in Gaza said the suspects had only been summoned for questioning about their activities. The suspects were warned Hamas would not allow any group to "take the law into its [own] hands and act in a way that harms Palestinian national interests," he said.

Hamas did not want to give Israel another excuse to attack the Gaza Strip, the official said.

"Apparently some Palestinian parties are trying to create an excuse for Israel to resume its aggression against our people," he said. "Hamas will not allow this to happen."

Khaled al-Batsh, a senior Islamic Jihad official, said that relations between his group and Hamas remained good despite the tensions.

He denied Hamas had Islamic Jihad men in prison. The tensions erupted when Hamas policemen briefly detained an Islamic Jihad member in the southern Gaza Strip, he said.

"It was an isolated incident," Batsh explained. "There are no tensions between us and Hamas."

The London-based, Saudi-owned newspaper Asharq Al-Awsat quoted a representative of Islamic Jihad's armed wing, the Quds Battalions, as saying that several members of the group were tortured by Hamas policemen.

The Hamas government in the Gaza Strip was following in the path of the Palestinian Authority in the West Bank by targeting members of the "Palestinian resistance groups," the official said.

The Hamas-run Interior Ministry, which is in charge of the movement's security forces in the Gaza Strip, denied the Islamic Jihad men had been tortured. The ministry did not say why they were arrested.