Hundreds of Pakistani refugees who spent weeks in relief camps began heading home to the battle-scarred Swat Valley today under a government repatriation programme.

But some refused to go back, saying they felt unsafe and needed promised aid, while the military tried to block thousands more returning without permission.

The government had designated today as the first day some of the more than two million people displaced during an army campaign to rid the north-western valley of Taliban could return home.

The army has declared most of Swat clear after an operation strongly backed by US officials eager to see Pakistan eliminate safe havens for militants blamed for attacks on international troops in Afghanistan.

Several families at some refugee camps said they would not go home unless they were given money, food and other government-promised aid.

Others also cited security worries. Many Swat militant commanders remain at large.

US-based Refugees International said the government was moving too quickly in reopening Swat, a former tourist haven. "The army's definition of cleared zones does not necessarily translate into safe zones for civilians," said a spokesman.