Hundreds of Pakistani refugees who spent weeks in sweltering relief camps began heading home to the battle-scarred northwest Swat Valley on Monday under a government repatriation program, traveling on buses with security escorts. But some refused to go back, citing security concerns and demanding promised aid, while the military tried to block thousands more returning without permission.In central Pakistan, meanwhile, an explosion destroyed a house used as a religious seminary, killing at least nine people - seven of them children - and leaving many others in critical condition in a reminder that security has deteriorated in areas well beyond the country's northwest region by Afghanistan. Police said they had evidence the home had been used as a meeting place for militants. The cause of the blast was unknown. The government had designated Monday as the first day some of the more than 2 million people displaced during an army campaign to rid the northwestern Swat Valley of militants could return home.Monday's sputtering start to the repatriation program, however, showed the government's limited capacity to respond to one of its greatest-ever humanitarian challenges. Pakistan's government has had a mixed record in such crises. Last year, officials told refugees from the Bajur tribal region they could return during a cease-fire with Taleban fighters, and many did, only to see fighting resume.
