The authorities in a Pakistani tribal region are repeating calls for thousands of Afghan refugees to return home. The North Waziristan tribal area bordering Afghanistan has been the scene of military attacks this month in which officials say nearly 200 pro-Taliban fighters have been killed. Officials have blamed unrest in the region on Afghans, thought to number several thousand, who first moved there when the Soviet Union occupied their country in the 1980s. On Monday, local state radio broadcast messages saying the Afghans must go.Zaheerul Islam, a leading government official in North Waziristan, said Afghans had been given deadlines to leave two or three times last year but had not done so. "Now they are not Afghan refugees but foreigners and must leave North Waziristan immediately," he said. "Severe action will be taken if they don't do so."