A senior Hamas official in the Gaza Strip on Saturday accused rival Fatah of plotting to assassinate Hamas leader Ismail Haniyeh as he prayed and said the would-be suicide bomber had been arrested and had confessed.

Tension between Islamist Hamas and Palestinian President Mahmoud Abbas's secular Fatah faction has increased since Hamas took control of the Gaza Strip in a brief but bloody civil war in June. Fatah still holds sway in the West Bank.

"There was a plan by a suicide bomber wearing an explosives belt to assassinate Haniyeh as he prayed in the mosque. He was arrested and confessed," Saeed Seyam, who oversees Hamas government security forces in Gaza and is a former interior minister in the Hamas government, told reporters.

Haniyeh was prime minister of the Hamas-led government which Abbas sacked after the Gaza takeover.

A Fatah spokesman dismissed Sayam's allegations. "We deny any involvement or considering any bomb plot in mosques against any Palestinian figure, whether it be Haniyeh or anybody else," Fahmi al-Zareer said.

"Fatah will never use this method of killing and assassination," he added. He accused Hamas of previously killing opponents in mosques in Gaza.

Seyam said the security officials who made the arrest had seized a video tape which showed the would-be attacker together with those training him.

He named a number of suspects but did not single out the identity of the would-be bomber. Seyam said another bombing had been planned to blow up Hamas television station headquarters in Gaza.

Seyam said Tayeb Abdel-Rahim, a senior Abbas aide, had been "involved and aware" of the plot against Haniyeh and had assured the would-be bomber his family would be looked after and moved to safety in the West Bank city of Ramallah.

Hamas has seen Abdel-Rahim as an arch-enemy since he oversaw a major crackdown on the group in 1996 when acting as a senior adviser to late Palestinian leader Yasser Arafat, after Hamas carried out a wave of suicide bombings inside Israel.

Abdel-Rahim was unavailable for comment on Saturday.

Zareer said Seyam's allegation "served to revive tensions" between the two groups.

Seyam said Ahmed Dughmush, a former senior Fatah security officer in Gaza, had been one of the masterminds of the assassination plot and that several others involved were still at large in the West Bank and in Egypt.

"According to the information we have, some of those at large are still determined to carry out a bombing in the mosque where Haniyeh attends prayers," he said.

Hamas police said they would reward anybody who gave information leading to their capture.

Last week a Hamas security official said the group had arrested a Palestinian with nine pounds of TNT ready to be detonated by mobile phone at a Gaza rally where Haniyeh welcomed home hundreds of Haj pilgrims.