..Lawyer Alec Muchadehama, representing the unionists, said that 12 people were now in hospital having been badly beaten while in police custody.
Police spokesman Wayne Bvudzijena said they were aware of the allegations and investigations were underway.
He added that "excessive" attitudes within the force were not condoned.
At least 50 people were arrested on Wednesday while trying to stage demonstrations to protest against the government's handling of Zimbabwe's economic crisis.
The government had said the protests were banned....