All banks in the Gaza Strip temporarily shut down on Thursday after Hamas-affiliated men forced a local branch to cash some $500,000 in checks.

Gaza bankers said the ruling Hamas militant group sent police to confiscate the money from a branch of the Palestine Investment Bank. They said the police were accompanied by members of a committee Hamas had appointed in 2009 to oversee the Palestine Investment Fund, which is run by the rival Palestinian government in the West Bank.

The men confiscated checks from the fund, and then ordered bank tellers to cash them, though the account didn't contain enough money. The bankers spoke on condition of anonymity for fear of retribution.

The Hamas Interior Ministry said the police helped to seize the money because the investment fund had improperly transferred funds out of Gaza to the West Bank. Hamas denied the money was taken at gunpoint.

The investment fund is one of the few institutions affiliated with the rival Fatah movement still operating in Gaza. After seizing power in Gaza in a violent takeover in 2007, Hamas shut down most agencies connected to Fatah, the party of Palestinian President Mahmoud Abbas.

Hamas has confiscated funds several times since the Hamas takeover, part of the bitter rivalry between the two dueling Palestinian governments. The Fatah-dominated Palestinian Authority now governs only in the West Bank.

The Palestine Monetary Authority, which regulates Palestinian banks, closed all Gaza branches Thursday to protest the confiscation. They are to reopen Sunday.