COLOMBO: Sri Lanka's top Tamil political force appealed Saturday for a way for cornered Tiger rebels to surrender to a third party and save tens of thousands of civilians trapped in the war zone. The Tamil United Liberation Front (TULF), a pro-government party, urged President Mahinda Rajapakse to name an international agency to which the Tamil Tiger guerrillas could hand over their weapons in exchange for an amnesty. The call came as government forces were poised for a final assault on a small patch of coastline into which the Liberation Tigers of Tamil Eelam (LTTE) are hemmed in the island's northeast. The United Nations estimates some 50,000 people are also trapped by the fighting and risk getting killed. International calls for a truce to allow the civilians out have been rejected by Colombo. "I suggest that an international agency, acceptable to the government, be selected to visit (the rebel-held area of) Wanni and persuade the LTTE to allow the innocent people to go out freely," TULF leader V. Anandasangari said. He said it should be accompanied by an offer of a general amnesty to those who surrender arms with a period of two weeks allowed for the process. "If such an arrangement is not made to bring out the civilians safely, the whole thing will end up in a national disaster detrimental to the good name of the country." The Tigers have been internationally condemned for holding the civilians as a human shield and Colombo has been under pressure not to use heavy weapons against the densely populated area. The government on Friday air dropped leaflets over the war zone urging civilians to leave and seek shelter in areas held by security forces. More than 110,000 civilians crossed the front lines and came over to government-held areas last month following a military push deeper into the remaining rebel territory.