(Bloomberg) -- Palestinian leaders in the West Bank and Gaza Strip have established police states that routinely arrest and torture their opponents, Human Rights Watch said in a new report.

The New York-based group found similar practices by the Palestinian Authority, which has governed the West Bank for 25 years, and Hamas, the militant Islamic movement that took over Gaza in 2007, according to a report released Tuesday in Ramallah.

“The attacks by both the Palestinian Authority and Hamas on dissidents and demonstrators, reporters and bloggers, are both systematic and unpunished,” Tom Porteous, deputy program director at Human Rights Watch, said in a statement. “Governments that want to help the Palestinian people develop the rule of law should not support security forces that actively undermine it.”

The Palestinian Authority and Hamas deny that abuses go beyond a few isolated cases that are investigated, the report said.

The 149-page report follows longstanding accusations that Human Rights Watch is one-sided in its condemnation of Israel’s treatment of the Palestinians. In 2009, a Human Rights Watch founder publicly accused the group of overlooking abuses by authoritarian regimes while it focused on Israel. In May, Israeli authorities sought to kick out Human Rights Watch’s local director, Omar Shakir, for having advocated in the past for an international boycott of the Jewish state; an Israeli court ultimately suspended the deportation order.

Threats, Beatings

In the report, Human Rights Watch says Palestinian forces often threaten, beat, and force detainees into painful or stressful positions for prolonged periods, even using cables or ropes to hoist their arms behind their backs. Security forces also routinely coerce detainees into providing access to their cellphones and social media accounts, it says.

Palestinians have gained “only limited power in the West Bank and Gaza, but yet, where they have autonomy, they have developed parallel police states,” Porteous said.

The report is based on interviews with 147 witnesses, as well as photographic evidence, medical reports, and court documents. The group met with the Palestinian Authority’s Intelligence Services in Ramallah, but said it couldn’t meet with Hamas officials in Gaza because of Israeli restrictions.

Human Rights Watch said both the Palestinian Authority and Hamas have mechanisms in place to take complaints from citizens and organizations about alleged abuses, but “these rarely lead to a finding of wrongdoing, much less disciplinary measures or prosecutions for serious abuses.”

To contact the reporter on this story: Jonathan Ferziger in Tel Aviv at jferziger@bloomberg.net

To contact the editors responsible for this story: Michael S. Arnold at marnold48@bloomberg.net, Mark Williams

©2018 Bloomberg L.P.