Human rights organizations have charged the two main Palestinian factions of detaining and torturing political opponents.
The Palestinian human rights group Al Haq says both Fatah and Hamas have detained more than 1,000 people in the past year, and that up to 30 percent of the detainees had been tortured.
Al Haq director Shawan Jabarin says the arbitrary arrests have become common since Hamas took control of the Gaza Strip in June of last year.
He says the most common forms of torture include severe beatings and tying detainees in painful positions.
Al Haq says the information is based on the testimony of 150 detainees.
Human Rights Watch is making similar allegations in a soon-to-be-released report.
The New York-based group is calling on Western governments to pay more attention to the abuses. It says funding for the Palestinians should be more closely linked to human rights improvements.
Meanwhile, the media rights group Reporters Without Borders has condemned the arrest of a Palestinian cameraman working for German television in the Gaza Strip.
The Paris-based group says masked men linked with Hamas took Sawah Abu Seif from his home Friday. The group says Hamas claims he is a Fatah supporter.
Reporters Without Borders calls the arrest "arbitrary and unjustified" and is demanding the cameraman's immediate release.
In the West Bank Monday, Fatah security forces loyal to Palestinian President Mahmoud Abbas arrested 50 suspected Hamas supporters.
In the past few days, Hamas has arrested more than 100 suspected Fatah supporters in the Gaza Strip. Hamas officials say they suspect Fatah was behind a bombing Friday that killed five Hamas members.
Some information for this report was provided by AP.