Camelia Pasandaran – Hundreds of residents of Siwalan village in Sidoarjo, East Java, assaulted a Koran study group on Saturday afternoon, injuring the group's leader and some of its members, over allegations that it was spreading unorthodox teachings.

"They demanded Majlis Tafsir Al-Quran [MTA] stop its activities for allegedly violating religious teachings, such as allowing dog [meat consumption] and forbidding tahlilan [a gathering to hold prayers for the dead]," Aan Anshori, the coordinator of Anti-Discrimination Islamic Network (JIAD), told the Jakarta Globe on Tuesday. The attackers were students from an Islamic boarding school, he said.

The angry mob also expelled several village residents who had joined MTA. He said the attack was not the first on MTA in Siwalan village – various attacks in East Java and Central Java have been reported, however.

"People's anger could not be held back any longer," Bahrul Ulum, a religious figure in the village told Indonesian news portal Detik.com on Saturday. "They're uneasy about MTA activities."

Agus Supriyanot, MTA's head who received three stitches after his head was injured in the attack, denied allegations that his group consumed dog meat. "It was an old issue, but they use it to attack us," Agus said. "We have clarified that it is not true."

He described a scene of fear and chaos outside the group's customary meeting place. "[Study group members] were chased and beaten," he said. "Around five members were injured. Some of the attackers were using iron bars."

But he conceded that disparities in religious practice may have motivated the violence. "The attackers could not accept our differences," Agus said. "When our members refused to join [tahlilan], they consider us deviant."

Muslims in Indonesia and some parts of Malaysia practice tahlilan, but it is not found in other parts of the Muslim world.

Aan said the police should increase security to prevent any future violent attacks against the study group. "People should engage in dialogue instead of violence to solve problems," Aan said. "If dialogue fails to solve the problem, they have to go through legal processes."

Buduran Police chief Cmr. Hendy Kurniawan said that some officers were assigned to guard MTA, but they failed to stop the angry mob.