Palestinian security forces arrested dozens of Hamas members in overnight raids in the Israeli-occupied West Bank, the largest security crackdown since 2007, officials said on Friday.
Adnan Al-Dmairi, security spokesman for the Western-backed Palestinian Authority, said the Hamas men had planned "to sow chaos" but he gave no specifics charges.
Islamist Hamas controls the Gaza Strip and is a rival of Fatah, the movement headed by Palestinian President Mahmoud Abbas which is dominant in the West Bank.
Though Abbas formally reconciled with Hamas last year to form a unity government, distrust remains.
"We are arresting them for interrogation or to put them on trial based on evidence they are threatening Palestinian internal security stability and are trying to drag the region and drag us into military confrontation and destroy the area," Dmairi said.
Hamas said 108 of its members were taken into custody in raids in towns across the territory. It said the raids were politically motivated and coordinated with Israel.
"Actions by these collaborator services will not break the movement and will not weaken resistance. We call for the immediate release of prisoners and we warn of the consequences of these unpatriotic measures," Hamas spokesman Abu Zuhri said.
An Israeli military spokeswoman said she had no information on the arrests, which took place two days after Israel said it had rounded up 40 Hamas men in the West Bank in the past few months, accusing them of planning attacks on Israel.
*This story was edited by Ahram Online.