Reclusive rebel leader Velupillai Prabhakaran was expected to pay tribute to the 241 suicide soldiers -- including 64 women -- who have died for their cause, at an undisclosed location in the rebel-controlled Wanni region in northern Sri Lanka.
Parades and remembrances were held across Sri Lanka's predominantly Tamil northeast.
In the restive eastern town of Batticaloa, a large float carrying portraits of suicide bombers paraded the streets and stopped near schools for children to offer flowers.
A split in the rebel group last year has resulted in factional killings in the town, 225 km east of the capital, Colombo.
The rebel stronghold of Kilinochchi was decorated with red and yellow rebel flags and senior rebels joined parents of the suicide bombers -- known as the Black Tigers -- for a public ceremony.
The first suicide attack came on July 5, 1987, when a rebel -- known as Captain Miller -- drove a truckload of explosives into a military camp, killing 40 soldiers.
Since then, 240 other rebels have blown themselves up in attacks that have killed Sri Lankan President Ranasinghe Premadasa, former Indian Prime Minister Rajiv Gandhi and dozens of others.
Gandhi died in 1991 when a Tamil woman blew herself up in southern India as she bowed to touch Gandhi's feet in a traditional gesture of respect.
Premadasa was killed in 1993 when a bomber on a bicycle approached him at a May Day parade. In 1996, bombers drove an explosive-laden truck into the Central Bank in Colombo, killing 91 and damaging the nearby 37-story World Trade Center.
Hundreds gathered to pay tribute to Captain Miller in the northern town of Nelliady, in the main Tamil heartland of Jaffna, where he attacked the military camp. Traditional bands beat drums while others carried posters of Miller.
The Tamil Tigers have been fighting since 1983 to create a separate state for ethnic minority Tamils, accusing the majority Sinhalese-dominated state of discrimination.
About 65,000 people were killed in the conflict before the two sides signed a Norway-brokered cease-fire in 2002. Peace talks came to a halt a year later, however, over disagreements on postwar power sharing.
Peace has largely held despite occasional violations.
