Voting was called off in the town of Salfit "because of problems and divisions," said Ahmed al-Deek, a senior Fatah official. Election officials said some ballot boxes had been torched but there was no immediate word on who was behind it.

Palestinian President Mahmoud Abbas suspended voting in the Gaza Strip and at several West Bank voting stations earlier in the week due to widespread fraud and violence.

In an attempt to salvage the primary vote which has highlighted widening internal rifts in Fatah, Abbas set up a review board to finalize a list of the party's candidates for a January 25 parliamentary election.

Fatah faces a strong challenge in the January poll from the militant Hamas group, which is running for the first time in a parliamentary election and enjoys a corruption-free reputation.

In Salfit, residents said gunmen were hovering in the vicinity of ballot stations, which also prompted the decision to suspend voting. The ballot was also called off in the West Bank city of Qalqilya due to disagreements over voter registration.

Voting in the West Bank cities of Hebron and Tulkarm was going ahead as planned, he said.

Last week, voters in primaries in some parts of the West Bank cast aside veterans in favor of newcomers and militants. Fatah's younger generation is challenging a dominant old guard, many of whose members are widely seen as tainted by corruption.

Public support for Fatah is already eroded by complaints of corruption and misrule, and new signs of disarray could boost Hamas after the Islamic movement's strong showing in municipal polls.

Palestinian gunmen stormed a government office in the Gaza Strip on Thursday to demand that the Fatah primary election be allowed to proceed after it was suspended due to violence and fraud.