Afghanistan's ruling Taleban militia has warned that any country which helps a US attack on Afghanistan will face retaliation, and has called on the world's Muslims to stand up and defend the country.

The warning appeared to be aimed directly at Pakistan, which said on Saturday it would lend its full support to international efforts to combat terrorism following intense US pressure.

Afghanistan is facing the growing possibility of US strikes as Washington confirms that Islamic militant Osama bin Laden, who is sheltered by the Taleban, is a prime suspect in Tuesday's devastating attacks.

Correspondents say scores of Afghans are now trying to leave the country.

Iran has just sealed off its 900km border with Afghanistan to stop a fresh influx of refugees from a country which has already suffered decades of civil war, famine, and currently drought.