India has blocked the release of a film about the assassination of former Indian prime minister Indira Gandhi, saying it glorifies her killers and could trigger violent protests.

India's film certification board said the movie glorified the two Sikh bodyguards who killed Mrs Gandhi to avenge her suppression of an insurgency which culminated in an army assault on Sikhism's holiest shrine.

The film, Kaum De Heere, or Diamonds Of The Community, was due to be released today.

Certification board chief Leela Samson said panel members saw the film and decided it could not be released as it poses a threat to public order.

Ms Samson said India's Home Ministry had expressed concern about an earlier clearance given to the film and asked the panel to review it.