COLOMBO (AFP) -- Sri Lankan troops have stepped up attacks against Tamil Tiger rebels killing at least 12 in overnight clashes across the northern district, the Defense Ministry said Friday.

The military said the rebels died in several clashes and placed government losses at one soldier injured in the 24 hours ending Friday morning.
There was no immediate comment from the Liberation Tigers of Tamil Eelam (LTTE) who have been fighting for a separate homeland for minority Tamils since 1972.
Independent verification of casualty tolls is rarely possible and journalists are kept out of rebel-held areas in the north.
Sri Lanka has vowed to pursue attacks against rebel positions until ""terrorism"" is completely defeated, prime minister Ratnasiri Wickramanayake told parliament Thursday, a day after twin bomb attacks rocked the capital Colombo.
At least 21 people were killed, including two who died in hospital on Thursday and a suicide bomber, while more than 40 were injured in Wednesday's blasts.
""We are sure of our targets, those are not civilian targets. We will continue air strikes until the terrorism is eradicated,"" Wickramanayake said responding to a motion moved by Tiger-proxy Tamil National Alliance (TNA).
TNA parliamentarian M. K. Sivajilingam asked the government to stop air raids in rebel-held areas as ""hundreds of civilians, including children and the elderly"" were being killed by the strikes and operations of army deep penetration units.
Sivajilingam said the government failed to pay compensation to victims of such attacks and their families and asked if Colombo considered these people citizens of Sri Lanka.