India's president has rejected the clemency petitions of three men sentenced to death for the assassination of former Prime Minister Rajiv Gandhi.

President Pratibha Patil's office said Thursday that she rejected their petitions last week.

The three men, all members of the Sri Lanka's Tamil Tiger rebel group, were given the death penalty in 1998 in connection with the former prime minister's assassination.

A female suicide bomber killed Mr. Gandhi in 1991 while he campaigned for reelection in southern India. The woman exploded a bomb wrapped around her waist as she knelt to touch Mr. Gandhi's feet.

The Tamil Tigers said they carried out the attack to protest the former prime minister's decision to send a peacekeeping force to Sri Lanka in order to help end the country's long-running civil war.

A total of 26 defendants were tried, convicted, and sentenced to death in the case. However, India's Supreme Court subsequently commuted the majority of the sentences to life in prison.

Rajiv Gandhi's mother, former Indian Prime Minister Indira Gandhi, was also assassinated. She was killed by her bodyguards in 1984. Rajiv Gandhi's wife, Sonia, is now the head of India's ruling Congress Party.