NEW DELHI (AP) — India’s president has rejected the mercy petitions of three men sentenced to death for the 1991 assassination of former Prime Minister Rajiv Gandhi, the presidential office said Thursday.

Gandhi was killed by a suicide bomber belonging to Sri Lanka’s Tamil Tigers while campaigning for his Congress party in southern India. The rebel group killed Gandhi in revenge for his decision to send Indian peacekeepers to intervene in the conflict.

A total of 26 defendants were sentenced to death in 1998 after a six-year trial. However, an appeals court commuted the sentences of 22 defendants to life imprisonment and another had her clemency plea accepted.

President Pratibha Patil’s office said that she had rejected the final three convicts’ clemency pleas last week.

FILE - In this Oct. 31, 2010 file photo, India's ruling Congress party President Sonia Gandhi, left, and her son Rahul Gandhi walk near the memorial of her mother in-law and former Prime Minister Indira Gandhi on her death anniversary in New Delhi, India. Pic:AP

The Gandhi family, no relation to independence leader Mohandas Gandhi, have been India’s main political dynasty since Jawaharlal Nehru became the country’s first prime minister.

Nehru died peacefully, but his daughter Indira Gandhi — India’s longest serving prime minister and Rajiv’s mother — was also assassinated 1984, by her Sikh bodyguards.

Rajiv’s widow, the Italian-born Sonia Gandhi, is the current leader of the ruling Congress party and his son Rahul is seen as next in line to be prime minister.