Palestinian rights groups say masked Hamas police beat and detained members of the Gaza Strip’s tiny Shia Muslim community during a religious commemoration last week.

It was the first claim of harassment by a group of Shia worshippers against the territory’s rulers, who are Sunni Muslims. Hamas officials denied the allegations. Hamas is believed to enjoy close ties with Iran, the Shia Islamic republic.

Rights groups reported on Tuesday a separate incident that also occurred last week – a knife attack on a local non-governmental organisation executive.

The accusations came as Hamas and Islamic Jihad, the main Palestinian Islamist movements, were holding talks about merging their two factions, according to sources on both sides.

A man who described himself as a Shia Muslim said police burst into a house where followers were marking Arbaeen, commemorating the end of 40 days of mourning following the anniversary of the death of Imam Hussein, the grandson of the Prophet Muhammad.

Complaints Filed

The man said about 15 worshippers were beaten and detained. He declined to be identified, fearing further harassment.

But some of the men filed complaints to the Palestinian Centre for Human Rights and the Al Mezan Centre for Human Rights, which both sharply condemned Hamas over the attack.

Mezan said in a statement that during Saturday evening’s incident in the town of Beit Lahia, police smashed up the apartment, broke the bones of seven of the men, detained some of them at a police station and beat them again before sending them to a military hospital for treatment.

"The attack is a violation of the freedom … to practise one’s faith," Samir Zakout, a Mezan official, said.

Ihab Ghussein, a Hamas interior ministry spokesman, said on Tuesday that police stormed the apartment of a group of "outlaws" who were planning "criminal acts".

He also said he was unaware of the presence of any Shia Muslims in Gaza and that his offices would look into right groups’ allegations that the men were beaten.

There are no official statistics on the number of Gaza’s Shia Muslims. They are believed to number several dozen – a minuscule minority among a population of 1.6 million people who are overwhelmingly Sunni Muslim.

Attack on Advocate

In Tuesday’s second incident, Al Mezan Centre said a prominent rights activist who has criticised Palestinian leaders and fighters, was attacked by unknown assailants.

Mahmud Abu Rahma, international relations director at the Al Mezan, was stabbed multiple times by several masked men on Friday evening, the Gaza-based centre said in a statement.

He was stabbed in the back, leg and shoulders, but used his laptop computer to prevent the attackers from stabbing him in the chest, the Palestinian Centre for Human Rights (PCHR) said in a separate statement on the incident.

"Mr Abu Rahma has received many threats on his mobile and email, including messages threatening his safety and life," the centre said, adding that the threats made reference to an article by Abu Rahma entitled "The Gap between Resistance and Governance".

The article, published in Arabic on several websites and later translated into English, warned that both the Palestinian "resistance" groups and government were failing ordinary citizens.

"Who will protect citizens from the mighty resistance and the powerful government when one, or both, of them harm them?" he wrote in an English-language version of the article published on January 5 by the Palestinian news agency Maan.

And he said Palestinian fighters endangered civilians by operating in crowded areas, creating the risk that their weapons would accidentally injure or kill locals, and raising the likelihood that Israeli response attacks would affect civilians.

Al Mezan said the attack was the second time Abu Rahma had been targeted since January 2. Ghussein, the Hamas spokesman, said the incidents were under investigation.

"The complaint was only filed yesterday," he told the AFP news agency, saying it was "surprising" that it took several days to be reported to authorities.

Hamas-Jihad Talks

On the political front, Gaza’s Hamas prime minister, Ismail Haniya, speaking during a meeting with senior officials from Islamic Jihad, called for "opening a serious dialogue to achieve the merger of the two movements", according to a statement from his office.

Islamic Jihad confirmed that talks to merge with Hamas were already under way.

"An in-depth dialogue has actually begun, both internally and externally, with the aim of uniting," Daud Shihab, a spokesman, said, referring to the group’s leadership which, like Hamas, is based in both Gaza and Damascus.

All previous attempts to merge the two Islamist movements had ended in failure, Shihab said.

He indicated that the current talks were taking place "at the highest level" among the leaders of both factions in Gaza and Damascus as well as among Islamist prisoners being held in Israeli jails.

Uniting the two movements would be "in the interests of both the Palestinian cause and the future of the Palestinian liberation movement, particularly in light of the Arab Spring", he said.

It was the first time Hamas and Jihad have spoken publicly about merging.

(Agencies via Al Jazeera)