sentences:  The demonstrators demanded the arrested ringleaders be returned to them and in a number of cases entered the police station, where (according to SMP officers) they tried to either block the foyer or gain access to the cells.Police on Nanking Road reported the crowd, which was between 1,500-2,000 strong, started good-naturedly but became more aggressive as arrests were made.After forcing protesters out of the charge room, a picket of police (there was only a skeleton staff of approximately two dozen officers overall, predominantly Sikh and Chinese, with three British officers) was set up to prevent demonstrators from entering the station.