A mortar shell struck the only functioning medical facility in Sri Lankas war zone on Tuesday,killing 49 patients and bystanders,a government health official said. It was the second time this month the hospital was hit. The attack,which also wounded 50 people,came after a weekend of heavy shelling that killed hundreds of civilians trapped in the tiny war zone. The military denied shelling the coastal strip under rebel control,which is packed with an estimated 50,000 civilians. Dr Thurairaja Varatharajah,the top government health official in the war zone,said a single mortar shell hit the admissions ward in the makeshift hospital on Tuesday morning. The death toll was expected to rise,he said. Shells were still hitting the area hours later,including one that landed about 150 yards from the hospital,Varatharajah said. Just outside the admissions ward little more than a corrugated tin roof with blue tarp walls bloody bodies were strewn about in the dirt while health workers hooked up the wounded to IV lines,according to photographs taken after the attack. Later,nearly two dozen dead bodies were lined up in rows in a sandy courtyard. Two other hospital officials,who spoke on condition of anonymity,confirmed the attack and said a hospital administrator was among those killed. It was the second time this month the facility has come under heavy fire. On May 2,64 civilians died when the hospital was hit by artillery. The military had denied any role and held the LTTE responsible. Meanwhile,military spokesman Brig. Udaya Nanayakkara said the forces were engaged in fierce fighting on Tuesday with the rebels which left 38 guerrillas dead as the Tigers deployed suicide bombers in desperate bids to stall the offensive. The three Black Tiger bombers blew themselves up before the advancing columns leading to the death of 10 rebels and injuries to several soldiers as troops moved another 1,000 metres in the four sq km area under the LTTE control,he said. The troops thrust,which was slowed down by suicide bombers and heavy mining,is bringing them closer to a direct confrontation with LTTE supremo Velupillai Prabhakaran and his aides,who the military claims are now trapped. The LTTE leadership,along with their second rung,remains in the small area, Brig Nanayakkara said. He denied the troops were responsible for the shelling at the hospital. We are not using heavy artillery, he said. Defence spokesman Keheliya Rambukwella described the report by the pro-LTTE web site TamilNet,which claimed the civilian deaths,as propaganda. International Red Cross confirmed there was firing in the area as UN Secretary General Ban-ki Moon said he was appalled at the killing of hundreds of civilians. Diplomats from Britain,France and Austria asked the UNSC to intervene to halt the fighting.