ANKARA, Turkey - Lawmakers voted early Thursday to approve a constitutional amendment allowing female students to enter universities wearing Islamic head scarves — a move some Turks see as a threat to the traditional separation of church and state.

The head scarf issue is a source of tension in Turkey and has divided the population among those who consider the ban an affront to the religious freedoms of pious Muslims and those who fear removing the ban would erode Turkey's secular education system.

Secularists regard the head covering as a political statement and argue it has no place in schools. They also fear that lifting the ban at universities would pressure all female students to cover themselves up.

On Wednesday, about 200 people gathered near the parliament building to protest the government's proposal as lawmakers convened. Hundreds of riot police, reinforced by armored vehicles, set up barricades to prevent them from marching to parliament.