The former president and PM later became bitter political rivals

Mrs. Kumaratunga, a member and a former leader of the Sri Lanka Freedom Party (SLFP) of President Mahinda Rajapaksa, said she was deeply concerned about violence, intimidation and corruption and urged her supporters to vote for the former army general, Sarath Fonseka.

She ruled the country for eleven years.

Her endorsement is seen as a big boost for General Fonseka.

Her father founded the SLFP, while both he and her mother were prime ministers, so the family has strong support.

United Nations Secretary General Ban Ki-moon earlier expressed alarm at the violence surrounding the run-up to Sri Lanka's presidential election.

He has urged all political parties and their supporters to "refrain from violence... and to avoid provocative acts throughout the election period".

At least four people have been killed in poll-related violence in the weeks leading up to the election.