[4][5] Seelan is also believed to have been responsible for the shooting to death of Sivashanmugamoorthy (alias Sundaram), deputy leader of People's Liberation Organisation of Tamil Eelam and editor of the Puthiya Pathai (New Way) magazine, at the Chitra Press in Jaffna on 2 January 1982.

[4][14] On 27 October 1982 Seelan led a group LTTE cadres (Aruna, Bashir Kaka Mahattaya, Pulendran, Raghu, Santhosam and Shankar) and attacked the police station in Chavakachcheri, killing three police officers (Kandiah, Karunanandan and Tilakaratne) and stealing a large amount of arms and ammunition.

[15][16] On 6 July 1983 a group of LTTE cadres, including Seelan and Sellakili (Sathasivam Chelvanayakam), stole five exploders from Kankesanthurai Cement Factory.

[18][19] Brigadier J. G. Balthazar, the commander of the Sri Lankan security forces in the north, received a tip-off from a police officer on 15 July 1983 that Seelan, the most wanted Tamil militant after Prabhakaran, was operating from a house in a coconut grove at Meesalai near Chavakachcheri.

[5][8][19][20][21] As the army arrived at the house that evening, Seelan and three other LTTE cadres (Anand, Aruna and Ganesh) fled on bicycles.

[20][22] As the soldiers pursued the LTTE cadres and opened fire, Seelan, who was handicapped by the injuries sustained at Chavakachcheri police station, abandoned his bicycle and ran through a paddy field.

[5][20] Aruna placed the barrel of his rifle on Seelan's forehead and shot him dead before escaping in a hijacked car.