An undercover police operation was mounted to catch vandals responsible for attacks on trams in Sheffield.
Officers from the Sheffield East local policing team, special constables and police cadets took part in a plain clothed operation where they travelled on a tram along the the centre centre-Manor Top-Gleadless route looking for vandals who have been hurling missiles.
A South Yorkshire Police spokesman said: "This operation was a direct result of youths throwing items at passing trams across the district and causing significant damage.
"Did you know that a tram windscreen costs over £1,000 to replace?
"We are working closely with Supertram in an attempt to prosecute offenders.
"On Sunday, we had our own tram and focused our patrols around the City Centre, Manor Top and Gleadless route.
"We will be increasing patrols on the tram network. We will be targeting those responsible for causing damage to your trams."
Anyone with information should call South Yorkshire Police on 101.