Human Rights Watch issued a statement on Wednesday urging Indonesian authorities to provide full protection for everyone attending the trial of 11 men charged with the deadly attacks on the Ahmadiyah community in Cikeusik, West Java, in February.

The US-based NGO said the trial, which starts on Thursday in Serang, Banten, could help stem violence toward Ahmadis if it met international fair trial standards and ensured the safety of victims, witnesses and court officials attending the court.

"For the Cikeusik trial to be a step toward ending religious violence in Indonesia, the police need to ensure the security of everyone in the courtroom," said Elaine Pearson, deputy Asia director at Human Rights Watch. "Witnesses brave enough to testify, as well as judges and prosecutors, should not have to face intimidation."

Three Ahmadis were murdered and five injured in Cikeusik on Feb. 6 when a 1,500-strong mob attacked 20 Ahmadiyah followers.

Recently, witnesses, judges and prosecutors were intimidated and harassed by Islamic extremists at a trial in Bogor, which saw three young men sentenced to between four and six months in prison.

In its statement, Human Rights Watch also said longstanding impunity for religious violence had fostered more attacks, possibly contributing to the suicide bombing at a mosque inside Cirebon Police Headquarters on Friday.

"President [Susilo Bambang] Yudhoyono should rein in Islamist militants before they claim more lives, and that starts with revoking policies that promote religious intolerance," Pearson said.

"The government should be aggressively prosecuting all those responsible for scores of attacks against religious minorities in recent years."