New Delhi, Apr 22 : Pushing forward his demand for an immediate ceasefire in Sri Lanka, Tamil Nadu Chief Minister M. Karunanidhi has called for a 12-hour strike in Chennai on Thursday.

Late on Tuesday night, Karunanidhi issued a final appeal and asked all Tamils, irrespective of their political affiliations, to join the strike.

He justified his decision saying that besides asking the Centre to demand a permanent ceasefire, the strike was also for sympathising with the plight of Tamils in that country.

The Dravida Munnetra Kazhagam (DMK) supremo clarified that the priority was not to ban the Liberation Tigers of Tamil Eelam (LTTE), but to save the lives of thousands of Sri Lankan Tamils.

In a telegram to Prime Minister Manmohan Singh, UPA chairperson Sonia Gandhi, External Affairs minister Pranab Mukherjee on Tuesday, Karunanidhi had urged the Indian government to issue a warning to Colombo to halt the war in Lanka immediately.

He had also asked the UN and the international community to intervene in the matter.

Meanwhile, according to reports, Senior Presidential Advisor and Parliamentarian, Basil Rajapaksa would visit India shortly as a special envoy of President Mahinda Rajapaksa for talks with the Indian authorities.

Earlier in the day, the number of civilians who have been evacuated and transferred to the government controlled ''safe zone'' in Sri Lanka rose to 80,000.

According to Defence sources, around 62,000 people had escaped the Tiger rebels-held areas earlier and till Wednesday morning, the Army was successful in rescuing
18,000 more civilians. The final assault against Prabhakaran began in Puthumattalam on Tuesday afternoon after the Lankan Army''s deadline for surrender of LTTE Chief Velupillai Prabhakaran ended after 24 hours. Puthumattalam is the last LTTE sand bund to be captured by Sri Lanka Army.

Sri Lankan Defence Secretary, Gotbaya Rajapakse had categorically said that Prabhakaran would now have to surrender or perish.

Rajapakse also stated that New Delhi is being kept informed about the military offensive on the Tamil Tigers.

However, the LTTE, on the same day specified that it would not surrender to the Sri Lanka armed forces, and added that their leader V. Prabhakaran was still alive and directing the counter-offensive in Puthumattalam despite an army noon deadline for surrender.

Monday saw a mass exodus of about 35,000 Tamil civilians fleeing the no-fire zones, a move looked upon by the country''s government as a sign of rebellion and thus signalling the LTTE''s end. (ANI)