Sri Lankan security forces on Thursday captured a key defence line of Tamil Tiger rebels after six days of intense fighting that left `scores` of guerrillas dead, the defence ministry said.

Government troops took a near five-kilometre (three-mile) front from the Liberation Tigers of Tamil Eelam (LTTE) following a new thrust that began on Saturday, the ministry said.

Despite the LTTE`s stiff resistance, troops captured the strategically important defence line from Muhamalai to Kilaly in the Jaffna peninsula, the ministry said in a statement.

`In continuous military thrust launched by 53 and 55 Divisions, terrorists were unable to defend their defence line,` the statement said adding that Tigers suffered `scores` of losses while troops `minimised` their casualties.

The statement came a day after the Tigers said they beat back a new push into their territory by government troops as heavy fighting raged across the island`s north.

There was no immediate comment from the Tigers to the latest military statement.

The rebels are locked in a decades-long war with the government to carve out a homeland for minority Tamils.