Afghan President Hamid Karzai brought help Monday for Pakistani victims of the massive earthquake that killed tens of thousands, as relief workers pulled more corpses from the rubble and the U.N. warned that 800,000 people remain without shelter. The U.S. Army began setting up a field hospital, and Pakistan's army will this week send another brigade of about 2,000 soldiers, including engineers, to Muzaffarabad, the capital of its portion of Kashmir _ to help in the relief effort and the grueling task of clearing debris, said army spokesman Maj. Farooq Nasir. Eighteen more bodies were found in collapsed buildings in the city on Sunday, he said. Two children from a displaced family suffered burns over 80 percent of their bodies when their tent caught fire at a camp near the northern town of Balakot late Sunday, said another spokesman, Maj. Gen. Shaukat Sultan. The family had reportedly fallen asleep with a lighted candle inside the tent. Army helicopters using night vision equipment quickly evacuated the children to a military hospital but one, a 12-year-old girl, died Monday morning from her injuries. The other, her brother aged about 7, is in critical condition. Seven other people burned in the fire were shifted to a hospital on Monday. Powerful aftershocks were still rattling the region more than two weeks after the 7.6-magnitude temblor wrecked a huge swathe of northern Pakistan and the divided Himalayan region of Kashmir, killing an estimated 79,000 people, including 1,360 on the Indian side. A magnitude-6.0 quake rocked Pakistani-held Kashmir on Sunday. No one was killed in that aftershock, but an earlier tremor killed five people in Afghanistan's eastern Zabul province near the Pakistan border. Trucks with emergency supplies were driving to the affected villages Monday where about 100 people were homeless and hundreds others were too scared to go back inside their mud-brick homes, said Ali Khail, a Zabul official. The Afghan president arrived in Islamabad on Monday for a one-day visit and talks with President Gen. Pervez Musharraf and Prime Minister Shaukat Aziz. Karzai brought five tons of medicines and medical equipment, as well as 30 doctors and nurses who will travel to the quake zone, said Rafiullah Mujaddedi, an official in the president's media department. Some 100 American soldiers arrived in Muzaffarabad on Monday in a 40-vehicle convoy to set up the Army's only Mobile Army Surgical Hospital, or MASH. Three isolation units had to be left behind as the winding road into Kashmir wasn't wide enough, but the MASH still has a capacity for emergency care and operations, and beds or cots for up to 84 patients.