Government artillery attacks and air raids inside Sri Lanka's northern war zone killed at least 38 civilians Wednesday and wounded 140 others, the area's top health official said, as the United States urged the government to protect civilians in military operations, according to AP. Dr. Thurairaja Varatharajah said 13 members of one extended family were killed in their sleep early Wednesday when artillery shells exploded on their home in a village inside a government designated «safe zone» in rebel-held territory. The bodies were brought to the makeshift hospital Varatharajah is running out of a school in the area, he said, adding that the shelling appeared to come from government-controlled areas to the south. Hours later, air force jets launched a pair of airstrikes in the area that killed 25 more civilians, whose bodies were brought to the hospital, he said. Witnesses in the area told him that as many as 80 civilians may have been killed in the strikes. Several people also have died of disease without medicine to treat their ailments and hundreds need to be evacuated, he said. State Department spokesman Gordon Duguid told reporters Wednesday that the United States has urged the Sri Lankan government to protect civilians during military operations. Duguid said the U.S is worried about the lack of access to people caught up in the war zone and asked both the government and the rebels to allow civilians to leave the territory. Military spokesman Brig. Udaya Nanayakkara denied targeting civilians, saying that the military only hit Tamil Tiger rebel positions. «Some air targets were engaged, but they are all LTTE locations,» Nanayakkara said, using the acronym of the rebels' formal name, the Liberation Tigers of Tamil Eelam. «There are no civilians where we are conducting operations, and these are fabricated stories.» Government forces have in recent months captured the rebels' main strongholds in the north and cornered them into a small sliver of land on the island's northeastern coast. But reports of rising civilian casualties have grown, with aid groups accusing the government of shelling the overcrowded war zone and the rebels of using the civilians as human shields and shooting at those trying to escape. Both sides deny the accusations. Aid groups say some 200,000 civilians are trapped in the small territory along with the rebels but the government puts the number less than 100,000. The government last week demarcated a 7.5-mile-long (12-kilometer-long) strip of land along the northeast coast as a refuge for civilians trapped inside the war zone. Varatharajah said that his hospital is again overcrowded with patients with more people seeking treatment for diseases caused by poor hygienic conditions, in addition to hundreds of wounded patients. He said 11 people, including four infants and an 8-year-old child, have died since Monday without proper treatment for diseases like diarrhea, pneumonia, meningitis and a lack of post-surgical care, as the makeshift hospital struggles with a serious drug shortage. About 350 people, including 12 children and 25 adults who need emergency care, need to be sent to better hospitals outside the war zone, he said. The Red Cross has so far carried out three sea evacuations of more than 1,000 patients and their relatives. The government has repeatedly denied reports of drug shortage. Meanwhile, Sri Lankan naval boats Wednesday accompanied an emergency Red Cross shipment of food aid for tens of thousands of civilians trapped in the war zone. The Red Cross said it was sending 30 tons of dry rations to the civilians in the north. Rebel political chief Balasingham Nadesan on Wednesday accused the government of creating a humanitarian crisis in the area. He denied U.N. accusations that it was recruiting child soldiers and holding the local civilian population as human shields against the government offensive. «The U.N. is accusing the wrong side in addressing the concerns of the people,» he told the rebel-linked Web site TamilNet. He also appealed for a truce, saying «the war has to be stopped immediately, paving way for negotiations.» Defense spokesman Keheliya Rambukwella rejected new calls for a cease-fire. The Tamil Tigers have fought since 1983 for an independent state for the country's ethnic minority Tamils. More than 70,000 people have been killed in the violence.