Toronto Police Chief Bill Blair admits police made a mistake in one of their most controversial tactics on G20 weekend.

More than 250 people were boxed in at the corner of Queen and Spadina in the pouring rain for hours on Sunday, June 27.

Many claim they were just passersby and were not given the opportunity to leave, although police say the crowd was asked to disperse several times.

This week, Blair justified his use of the technique, known as kettling, but admits the people should never have been held there as long as they were.