Islamic Hamas movement, which controls the Gaza Strip, stepped up a crackdown against members and supporters of Palestinian President Mahmoud Abbas's Fatah party there, a source said on Thursday.

The source said that the internal security service of Hamas summons Fatah partisans during the day and releases some or most of them in the night. According to him, these actions have been repeating for several weeks.

"The number of detainees is not stable, it increases and decreases continually," the source, who spoke on condition of anonymity, said, "There are arrests and releases everyday but arrests are becoming more common and prevalent."

The crackdown spread as the two movements failed to reach a reconciliation agreement in Egyptian-brokered negotiations in June. A new round of talks is scheduled on July 25 in a bid to end the feud started from June 2007, when Hamas routed pro-Abbas forces and seized Gaza.

"Most of those summoned have to face insult and humiliation apart from abuse and torture," the source added.

Local rights group here said Hamas had been barring their lawyers from seeing the detainees. "We've contacted the authorities to visit our clients but we haven't got any response," said Issam Younis of al-Mezan Human Rights Center.

Younis added that the Hamas interior ministry doesn't disclose the places where it holds Fatah activists. But a number of people who were freed recently told Xinhua that Hamas had held them in Abbas's beach-side house in southwestern Gaza city.

Hassan al-Seifi, the general inspector of the interior ministry, denied "the accusations "the rights groups and Fatah have raised." The government has found new but temporary detention facilities after its stations were destroyed," al-Seifi said, referring to a January Israeli offensive in the Hamas-ruled territory.

He also rejected reports of torture. "There is a strict surveillance in the detention places and those who complain about this (torture) must bring a proof."

On June 6, Hamas launched a wide crackdown on Fatah supporters and former members of pro-Abbas forces apparently in response to deadly clashes between Hamas and those forces in the West Bank where Fatah has been holding sway.

On Wednesday, Fathi Hammad, Hamas' interior minister, said "the arrests have targeted elements that had planned to destroy the security in Gaza Strip."

"The terror networks had monitored the movements of Hamas leaders and officials in Gaza and sent them to Ramallah as part of the security liaison with Israel," Hammad said.

Deposed Hamas' premier Ismail Haneya and Hamas' lawmakers were among the people the Fatah guys had watched, Hammad added.

But Zakareya al-Agha, Fatah representative in Gaza, said Hamas arrests Fatah people to revenge the Palestinian National Authority (PNA)'s security campaign in the West Bank.

"Hamas has told us that the Gaza arrests are part of reaction to what is going on in the West Bank," al-Agha told Xinhua. "This means that there are no legal justifications for this crackdown."

Hamas accuses Fatah of holding nearly 1,000 of its members and supporters in the West Bank. Sami Abu Zuhri, a Hamas spokesman, also said the PNA tortures Hamas' prisoners there.

(Xinhua News Agency July 10, 2009)