Israeli forces raided the offices of three Palestinian non-government organisations overnight, confiscating computers and other material, one of the groups said on Tuesday.
"At 3:00 am this morning, 11 December 2012, the Addameer Prisoner Support and Human Rights office was raided by the Israeli Occupation Forces (IOF)," the Addameer group said on its website.
"Four laptops, one hard disk and a video camera were taken among other materials. The IOF destroyed the office," the group added, saying desks and "ransacked filing cabinets" were left scattered after the raid.
"At this moment, we are not clear as to what has been confiscated," it said, adding the raid was the first time the group's Ramallah offices had been targeted by Israeli forces since 2002.
The Israeli military said it was checking reports of the raids, which Addameer said also targeted the Ramallah offices of the Union of Palestinian Women's Committees and the Palestinian NGO Network.
"Addameer condemns this attack on human rights and civil society organisations, and sees it as an attempt to cripple solidarity with the prisoners movement," the group said.
Although the West Bank city of Ramallah nominally falls under full Palestinian administrative and security control, Israeli forces regularly carry out raids in the city and its surroundings.
Addameer (Arabic for conscience) is a prominent Palestinian NGO campaigning for rights of Palestinians held in Israeli jails.