BELGRADE, Serbia –  State prosecutors opened a criminal investigation on Tuesday against the leader of a far-right group for orchestrating anti-gay protests that turned violent in downtown Belgrade.

More than 150 people were injured on Sunday in running battles with police as thousands of far-right demonstrators tried to disrupt a gay pride march by hurling Molotov cocktails and stun grenades.

Mladen Obradovic of the Obraz, or Honor, group is suspected of "violent conduct" during the clashes.

The state prosecutors' office said another 130 people are under investigation for trying to disrupt the pride march and 66 of them were on Tuesday ordered to 30 days in prison each as a pretrial detention measure.

If charged and convicted, Obradovic and the others could face up to 12 years in jail.