Colombo, July 5 (PTI): Sri Lanka's Tamil Tiger rebels today marked the 20th anniversary of their first suicide bombing by admitting that they used 61 suicide bombers in the past year despite a truce.

The Liberation Tigers of Tamil Eelam (LTTE) said they were commemorating 322 Black Tigers, or suicide bombers, who perished since their first attack 20 years ago.

Last year, the Tigers honoured 261 suicide bombers and this year the number shot up to 322 showing that 61 suicide bombers perished in the past 12 months despite a Norwegian-arranged truce.

The bloodiest Black Tiger attack took place on October 16 last year when two Tigers drove a truck bomb and killed 116 sailors waiting for transport to go home at the north-central town of Dambulla.

Sri Lanka has stepped up security for the Black Tiger anniversary.