Fifteen people have been arrested after rocks were thrown at police and a patrol car set on fire in Yamba this morning.

About 2.30am, police from the Coffs/Clarence Local Area Command went to a party being held at an industrial complex on Deering Street at Yamba with about 100 people in attendance.

When the officers arrived they were confronted by a group of about 20 people, who armed themselves with bricks and began smashing the windows and panels of the police car.

When the officers attempted to intervene, they had rocks and bricks thrown at them.

To avoid injury the officers left area on foot. Their patrol car was then set on fire by the crowd and was destroyed.

Another police vehicle came to their aid and was also pelted with rocks and bricks.

Police from across the command responded to the incident and arrested 15 people, including the owner of the complex, aged in his 30s, and his wife. Most are aged in their 20s.

Those arrested have been charged with affray, with the majority being bail refused to appear at Grafton Local Court later today.

More charges are expected to be laid.

The damage to the two police cars is estimated at being more than $50,000.