Sri Lanka will re-deploy thousands of elite police commandos from the country's east and move them north to help combat Tamil Tiger rebels as civil war fighting intensifies, security forces said on Friday.

Around 2,000 Special Task Force police, or STF, would move from formerly Tamil-controlled eastern provinces, now held by government troops, to areas threatened by Tiger fighters in the north, the military said.

"By redeploying the STF we will be able to free some troops for future operations in other areas," military spokesman Brigadier Udaya Nanyakkara told Reuters.

Since the 2006 resumption of a 25-year civil war between ethnic Tamil separatists and government forces in which 70,000 people have died, the military has recaptured the country's east.

Security forces are now pressing back Tiger rebels in their northern strongholds and have vowed to end the bloody conflict by this year or early in 2009.

Nanyakkara said 50 Tiger separatists had been killed in fighting since Wednesday, although casualty numbers are hard to verify since Nordic ceasefire monitors left the country after the government abandoned a truce agreement in January.

Both sides regularly inflate the numbers of those killed by their own fighters to maintain frontline morale. A Tiger spokesman could not immediately be reached to verify the military's claim.

But as the conflict turns increasingly vicious and atrocities blamed on both sides by international rights monitors mount, a police spokesman said recent local elections in the east had brought a degree of security "normalcy".

That would allow regular police to replace the STF in some eastern areas, the spokesman said. Government forces have claimed full control over the area since mid-last year.

Re-deployed STF commandos would help end a spate of roadside bombings by the Tigers, targeting what he said were mainly civilians in the northern districts of Vavuniya and Anuradhapura, Nanyakkara said.

Government-backed former rebels won nine local contests in March in a dry run for wider provincial elections in May underpinning the government's aim to defeat the Tigers using both the ballot box and the current offensive.

The result was a blow to the Tigers, who are fighting for an independent homeland in the country's north and east.