UNITED NATIONS (AP) -The U.N. Security Council is demanding that Tamil Tiger rebels in Sri Lanka stop fighting and allow tens of thousands of civilians being used as human shields to leave the war zone.

It is also calling on the government to stop firing heavy weapons, to help trapped civilians evacuate, and to allow urgent delivery of humanitarian aid.

The council press statement expresses grave concern at the worsening humanitarian crisis in northeast Sri Lanka where the Tamil Tigers have been pushed into a tiny area by government forces. The statement is not legally binding.

AP-ES-05-13-09 1758EDT