Palestinian forces have arrested around 100 Hamas members in the West Bank, a security official said Friday, raising tension between the Islamist movement and its Ramallah-based rivals.
The people, arrested overnight, "intended to carry out attacks against the Palestinian Authority (PA)," the official said, without elaborating.
Hamas spokesman Sami Abu Zuhri condemned the arrests as a "dangerous escalation which blocks efforts and reconciliation."
He also criticised the PA for its "security cooperation with the Israeli occupation."
Under 1993 peace accords, the PA coordinates on West Bank security with Israel, including by sharing intelligence.
The PA is dominated by Palestinian president Mahmud Abbas's Fatah party, which is Hamas's bitter rival. It regularly arrests members of the movement, but as many as 100 members in one swoop is rare.
In June 2014, Israel detained hundreds of Hamas members in the West Bank after blaming the group for the kidnap and murder of three Israeli teenagers.
The latest arrests came amid tension between Hamas and the West Bank-based PA, more than a year after the two sides signed a unity deal that failed to end a years-long Palestinian split.
In April 2014 Fatah signed a unity deal with Hamas, which controls the Gaza Strip.
The two sides approved a government of independent technocrats to take over administration of the Gaza Strip, Hamas's bastion, and the West Bank.
But disputes over the payment of Hamas-appointed employees in Gaza, and control of the territory, mean Hamas remains in control of the enclave.
Last summer's war between Israel and Hamas also set back any efforts at reconciliation.