French police say they have arrested about 300 people after violent anti-NATO protests in Strasbourg. The clashes come as leaders from the 28-member alliance gather in the French city for a summit marking the 60th anniversary of NATO's founding.

The demonstration had turned violent after police prevented an estimated six hundred protesters from marching into downtown Strasbourg Thursday evening.

Masked activists wielding wooden clubs smashed bus stops and hurled rocks, breaking windows along the way, according to authorities. Police reportedly fired tear gas to break up the protests.

Police say order was restored by early evening on Thursday and that more than 100 people were taken into custody.

Major security measures have been put in place to guarantee the safety of world leaders during the two-day summit. While most of the talks will be held in Strasbourg, there will also be meetings in the German town of Kehl and the city of Baden-Baden, across the French border.

About 100 demonstrators gathered in Baden-Baden on Thursday for a peaceful anti-NATO protest, calling for the abolition of the military alliance.

db/sh/th, dpa/afp