On Monday, the Sri Lankan government issued a 24-hour ultimatum for the Tamil Tiger rebels to surrender. Defence ministry spokesman Keheliya Rambukwella warned leader V. Prabhakaran to lay down his arms by Tuesday afternoon. The government said troops had breached a key fortification built by the Tigers to defend their last strip of land. At least 35,000 civilians have now managed to flee the confliict zone, according to an aerial video footage released by the authorities on Monday. Speaking with reporters, President Mahinda Rajapaksa said the mass exodus indicated that people were defying the rebels. He claimed again that a "complete defeat" of the Tigers was imminent.