Sri Lanka sealed off roads and deployed 19,000 soldiers and police in the capital Sunday to prepare for a summit of South Asian leaders amid a raging civil war. Violence in the Indian Ocean nation's quarter-century civil war has escalated in recent months, with near-daily airstrikes against ethnic Tamil rebels, gunbattles in the volatile north and a series of bomb and suicide attacks in Colombo and its suburbs. The Tamil Tiger rebels offered a unilateral cease-fire that began Saturday as a goodwill gesture during the summit of the South Asia Association for Regional Cooperation, known as SAARC. But the rebels said they would defend themselves if the government continues its offensive against their de facto state in the north. Government officials said the rebels were simply trying to buy time to regroup after a series of battlefield losses, and some ministers have said the army has no plans to back off. Despite the cease-fire, there were scattered battles Saturday along the northern front lines, where army troops killed 12 rebels, said military spokesman Brig. Udaya Nanayakkara. Rebel spokesman Rasiah Ilanthirayan was not immediately available for comment. Foreign Minister Rohitha Bogollagama said the summit, which is to address a food and energy crisis and other issues, would play an important role for regional cooperation. “This is the largest ever SAARC summit to be held,” he told reporters Saturday, adding that “security must be the ultimate.” The summit began with low-level meetings Sunday and foreign ministers are to arrive later in the week. The heads of state hold their two-day meetings starting next Saturday. The regional body – set up in 1985 to promote economic cooperation – consists of India, Pakistan, Sri Lanka, Nepal, Bangladesh, Bhutan, Afghanistan and the Maldives. Sri Lanka hopes to showcase its recent successes against the Tamil Tigers and prove to the delegates it is able to operate normally despite the civil war. A rebel bus bombing or attack during the gathering would deeply embarrass the government. Around 12,000 police and 7,000 troops have been deployed in Colombo to provide summit security, Nanayakkara said.