Hamas gunmen killed at least eight members of Mahmoud Abbas’s Presidential Guard on Tuesday, security officials said, as Palestinian factional fighting threatened to spill into full civil war.

The battle, at a Presidential Guard training base near the Karni Crossing, Gaza’s main commercial lifeline with Israel, erupted despite a renewed pledge by warring groups to pull gunmen off the streets. “They are attacking the headquarters and the crossing with RPGs (rocket-propelled grenades) and mortar bombs... I warn of a massacre here (by Hamas),’’ Ali al-Qessi, a Presidential Guard spokesman said in a call for help on Palestinian television.

Security officials said eight members of the presidential force, heading to the training base to help their comrades, were ambushed and killed by Hamas gunmen near Karni.
The US has earmarked millions of dollars to provide training and non-lethal equipment to the Presidential Guard, which is comprised of members of Abbas’s Fatah faction and widely seen as a counterforce to armed Hamas groups.

Islamist Hamas and secular Fatah formed a unity government two months ago in a deal brokered by Saudi Arabia.

Challenge to Hamas
In a challenge to Hamas, a 450-strong contingent of Fatah fighters, who had been receiving advanced training in Egypt, entered the Gaza Strip through the Rafah border crossing with Israeli approval, Western sources said.  The Fatah men could be used as possible reinforcements in the fighting against Hamas militants.

Meanwhile, Palestinian leaders renewed their appeals for calm in speeches marking the annual ‘Naqba’, or what Palestinians describe as the tragedy that befell them when Israel became a state in 1948. Abbas, in a speech, called on rival factions to ‘’fully safeguard calm so that Palestinans can resume the path of reform and development to minimise unemployment and reduce the cycle of poverty’’.

Masked gunmen ruled Gaza. Residents who risked leaving home darted across streets, shoulders hunched, to the crackle of volleys from automatic weapons. The Ministry of Interior in Gaza and positions of Hamas’s Executive Force came under fire from gunmen armed with assault rifles and rocket-propelled grenades. Hamas blamed Fatah for the attack, in which no one was hurt.

In a separate incident near Karni, Israeli forces shot dead a Palestinian, hospital officials said. An Israeli army spokeswoman in Tel Aviv said soldiers spotted gunmen moving towards the border fence and opened fire, hitting one of them.