Despite its anti-Israel stance, the nongovernmental organization Human Rights Watch accused the Palestinian Authority on Tuesday of violently stopping dissent.

“Twenty-five years after Oslo, Palestinian authorities have gained only limited power in the West Bank and Gaza, but yet where they have autonomy, they have developed parallel police states,” said Tom Porteous, deputy program director at Human Rights Watch. “Calls by Palestinian officials to safeguard Palestinian rights ring hollow as they crush dissent.”

The New York-based group “interviewed 147 witnesses, including former detainees and their relatives, lawyers, and representatives of nongovernmental groups, and reviewed photographic evidence, medical reports, and court documents.”

“Systematic arbitrary arrests and torture violate major human rights treaties to which Palestine recently acceded,” added HRW. “Few security officers have been prosecuted, and none have been convicted for wrongful arrest or torture, as far as Human Rights Watch has been able to determine.”

HRW called on the United States, the European Union and others to halt assistance to “specific units or agencies implicated in widespread arbitrary arrests and torture” by Hamas and the P.A. until the practices cease and the perpetrators are held accountable.

The P.A. was taken aback by the findings.

“What HRW did is a political act and not a legal act,” said Adnan Damiri, spokesman for the P.A. security services. “I’ve never heard of human rights groups calling to stop financial aid before.”