Because the fight was so heavy the riot police could look on only.

Riot police were called out, but there was no violence.

He was carrying a long staff of the sort used by riot police.

Riot police turned out in force, prepared for the fight.

Riot police had to come in and the game was abandoned.

The number of riot police stood at about 300 fighters.

Riot police were called to protect the election commission building.

Riot police were called, and they eventually carried the men to safety.

I think we'd need riot police at the polling places.

Sometimes riot police or other forms of law enforcement become involved.