Afghan refugees ordered out of a Pakistani war zone have begun flowing over the border into their homeland, worsening a humanitarian crisis resulting from an army offensive against Taliban militants, officials said.

A suicide car bomber attacked an army convoy in Pakistan’s volatile north-western tribal area today, killing three civilians and three soldiers, an army spokesman said.

Pakistani security forces killed 10 suspected militants and wounded 25 others today in new clashes near the Afghan border, a government official said.