COLOMBO, April 30 (Xinhua) -- Sri Lanka's military says the troops have reached the final phase of its military thrust against the Tamil Tiger rebels.

    "During the past 48 hours security forces led by 58 Division infantrymen have advanced further South of Rektavaikkal, shrinking the remaining swathe of land where LTTE terrorists are expected to face its end game," a defense ministry statement said here Thursday.

    The Army's 58 Division troops advancing south and the 53 Division flanking west of Vellamullivaikkal have been spearheading the rescue operations as an estimated number of 15,000-20,000 civilians await liberation from Liberation Tigers of Tamil Eelam clutches," an unnamed official said.

    At least 15 rebels were killed and another 20 injured during confrontations ensued between troops and LTTE in general area Karayamullivaikkal on Wednesday.

    The troops also had braved over half a dozen suicide bomb attacks including ramming of two explosive laden vehicles by the LTTE during the last two days.

    Sri Lankan government has stressed that it would not bow down to international pressure to halt the current military operations.

    President Mahinda Rajapakse on Thursday ruled out halting the offensive and warned the rebels that they only had a "little time left" to surrender.

    He was echoing his brother Gotabhaya Rajapakse's thoughts who told the visiting foreign ministers of Britain and France that the government would not bow to the international pressure to provide recess to the rebels who have neared the end of their over three-decade fight to carve out a separate homeland for the minority Tamils.

    The government maintains the military operations are now limited to rescuing a large number of civilians held hostage by the LTTE in the narrow coastal strip of Puttumatalan in the northeastern Mullaithivu district. Over 115,000 of them had arrived in the government areas since 20 April.