Palestinian President Mahmoud Abbas launched a bitter attack Tuesday on the Hamas movement, which controls Gaza, as a divided nation marked the fourth anniversary of historic leader Yasser Arafat's death. Abbas accused Hamas of sabotaging efforts to mend the rift in Palestinian ranks created by its seizure of Gaza last year and of using force to prevent any commemorations for Arafat in the coastal territory.

Speaking at Arafat's graveside at his political headquarters in the Occupied West Bank city of Ramallah, Abbas blamed Hamas for the abandonment of planned reconciliation talks due to have been held in Cairo Sunday, accusing it of "not wanting dialogue."

He charged that the Islamists had invented "false pretexts" for not showing up at the talks with other Palestinian factions. "They missed this opportunity and I am talking of the Hamas leadership here," he said.

Abbas again insisted that his security services were not holding Hamas activists as "political prisoners" in the Occupied West Bank as the Islamists claim.

Hamas responded by accusing Abbas of being the leader within his Fatah faction of "a current complicit in the plans of the Americans and the Zionists."

In a statement issued in Gaza, it also accused the Palestinian police of "working to protect the security of the [Israeli] occupier and not of the Palestinian citizen."

Abbas also accused Hamas of blocking any commemorative events for Arafat in Gaza "under the threat of armed force."

Unlike in the Occupied West Bank, where thousands of Palestinians turned out to hear the Abbas address, which was also carried live by Palestinian television, no events were planned in Gaza.

An organizing committee made up of all the main Palestinian factions except the Islamists accused Hamas of refusing authorization to hold any commemoration in the territory.

But the Hamas-run Interior Ministry in the Gaza Strip said it had received no such request and that it had a responsibility to maintain order.

Last year, a massive memorial rally in the coastal enclave was marred by violence when Hamas police opened fire on the crowd, killing eight people and wounding 130.

The Islamists seized power in the territory in June 2007 after a week of deadly fighting with forces loyal to Abbas' secular Fatah faction. Hamas, which won parliamentary elections in 2006, were reportedly spurred into action after reports emerged in the Arab press of an impending US-backed offensive by Fatah aimed to rout the Islamists from Gaza.

The takeover, which confined Abbas' rule to the Israeli-occupied West Bank and split the Palestinians into two hostile camps, was followed by the ransacking by Hamas supporters of Arafat's former residence in the Gaza Strip.

Nayef Harbiyat, 83, who had traveled to the ceremony in Ramallah from Dhahiriya at the other end of the Occupied West Bank, bemoaned the loss of the Palestinian leader. "With every year that has passed, people realize how much he protected our people," he said. "Four years after his death, we are enduring insurmountable divisions."