Sri Lankan Navy early on Saturday fired at and destroyed three suspected Tamil Tiger boats in the seas off the capital Colombo, said the military.
Brigadier Prasad Samarasinghe, the military spokesman said that three suspicious boats were spotted close to the restricted zones of the capital around 5:30 a.m. local time (0000 GMT).
The Navy pursued and destroyed one boat around six nautical miles (about 11 km) off the coast.
The two other boats were pursued and destroyed at 11 nautical miles (about 20 km) and 14 nautical miles (about 26 km) respectively in the deep sea.
Samarasinghe said the Liberation Tigers of Tamil Eelam (LTTE) was behind the attempted attack.
The Navy was conducting search operations in the area, said the spokesman.
The incident came about one week after the Army captured a major LTTE stronghold in the east.
The fall of Vakarai was the second loss for the LTTE in the Eastern Province since September last year and was seen as the biggest gain for the military since the ongoing truce agreement came into force in 2002.
Continuation of violence despite the stalled Norwegian backed peace process has claimed over 3800 lives since December 2005 in the Indian Ocean island.