Air force MIG Jet aircraft attacked a Liberation Tigers of Tamil Eelam (LTTE) training camp in Vavuniya, 254 kilometres (159 miles) from the capital, the defence ministry said in a statement.
It gave no further details.
The raids came after Colombo said it had escalated attacks against the Tigers on Wednesday, sinking two rebel boats and destroying a large ship carrying shells believed intended for the Tigers.
At least 15 rebels died in Wednesday's sea attacks while three rebels were shot dead by a police commando foot patrol.
There has been no comment from the rebels on the two days of attacks.
Meanwhile, in the eastern district of Trincomalee 257 kilometres (160 miles) from the capital, two Muslim traders were found shot dead by unidentified gunmen, police said Thursday, adding that an investigation was underway.
Sri Lanka has stepped up sea and land attacks against the LTTE after the rebels shelled helicopters carrying diplomats and a minister on Tuesday.
Tuesday's attack was