MORE than 80 youths were detained last night as police launched an unprecedented clampdown on anti-social behaviour.

In a show of strength, police chiefs deployed aircraft, horses and a dog to round up suspected troublemakers.

The clampdown by Cleveland Police was on a scale never seen before and its success will be closely watched by forces throughout the country.

Officers invoked special powers to stop and search gangs of youths in Newham Grange Park, in Stockton, the scene of recent disturbances.

They said the operation was designed to send a message to troublemakers that police were no longer prepared to tolerate bad behaviour.

In a carefully-scripted move, police sealed off every park exit before sending in teams to comb the area.

To counter any attempt at a mass escape, mounted officers and a dog-handler were also brought in, while a spotter aircraft circled above the park. Teams also used heat-sensitive cameras to pick out anyone attempting to hide.

Senior officers spent days planning the crackdown - codenamed Operation Night Owl. The move follows disturbances last week when rival gangs clashed in the park and mounted police and a police car came under attack.

Two girls in the park also suffered minor injuries when someone threw a firework.

Between 100 and 200 youths were involved in running disturbances, and there were fears there could have been a bigger turnout last night.

Inspector Mick Williams said that the purpose of Operation Night Owl was to show the youngsters that rowdy behaviour was unacceptable.

"We are not trying to scare people and this is not trying to police a violent football match," he said. "We are mindful that our officers are dealing with children."