Universities in Turkey are threatening students with expulsion if they take part in demonstrations on or off campus.

New rules have been introduced following a number of student protests in recent months against a ban on the wearing of Islamic headscarves on college premises.

The BBC correspondent in Ankara says the move by the higher education authorities appears to be targeting Islamist influence in academic life.

In future, when students register at a university, males will have to submit photographs of themselves without beards, females without headscarves.

The authorities say they want to stop what they regard as the exploitation of students by outsiders for political purposes.