It occurred on 11 December 1996 in which the LTTE militants attacked and overran the Special Task Force detachment at Pulukunawa in Ampara.

[3] In the early hours of 11 December 1996, the LTTE militants numbering over 500 which included female cadres began their attack on the STF detachment.

They were able to capture the 85 mm field gun and 165 85mm shells, a 81mm mortar and over 70,000 small arms ammunition.

Reinforcements soon recaptured the camp and the Sri Lanka Army launch Operation Singing Fish to clear Unnichi jungles from where the LTTE came from.

Sirimanna, who was commanding the artillery unit was posthumously promoted to the rank of Major after he died defending his gun along with eight gunners.