India's film certification board has blocked the release of a film on the 1984 assassination of former Indian Prime Minister Indira Gandhi, saying it glorifies her killers and could trigger violent protests, officials said.

The board says the film glorified the two Sikh bodyguards who killed Gandhi to avenge her suppression of an insurgency that culminated in an army assault on Sikhism's holiest shrine, the Golden Temple.

The film "Kaum De Heere", or "Diamonds of the Community", was scheduled to be released on Friday.

Leela Samson, who heads the certification board, says panel members saw the film and decided it could not be released as it poses a threat to public order after India's Home Ministry expressed concern.

"The film is double trouble. It glorifies Indira Gandhi's assassins who took the law into their own hands and it glorifies the hanging of the two men," Samson said.

Golden Temple attack

The film is based on the lives of three Sikh men, including two bodyguards who shot and killed Gandhi against the backdrop of an insurgency that gripped the northern state of Punjab through the late 1970s and early 1980s when Sikh groups demanded a separate Sikh nation.

Gandhi ordered the June 1984 army operation to flush out hundreds of heavily armed Sikh fighters barricaded inside the Golden Temple.

The attack outraged Sikhs and led to a catastrophic breakdown in communal relations.

Later that year, Gandhi was assassinated and the country was swept by a wave of anti-Sikh rioting which resulted in the deaths of more than 2,000 Sikhs.

Officials said the recent arrest of India's chief film censor on accusations that he solicited bribes to speed the clearance of films drew attention to the clearance given to "Kaum De Heere".

Meanwhile, leaders of India's ruling Bharatiya Janata Party and the main opposition Congress Party have called for the banning of the film, saying it would offend people's religious and community feelings.

Pradeep Bansal, the film's producer, said the film was based on historic events and that he would soon seek a review of the film board's decision.

"It is a balanced film. Some people are unnecessarily trying to create a controversy," Bansal told reporters.