Police today warned "summer holiday vandals" to stay off railway property after three trains were stoned in Bradford in an hour.

British Transport Police are hunting yobs who struck at passing trains at Apperley Junction.

The attacks came at a time when bored youths traditionally venture on to rail property.

The 4.45pm Leeds to Bradford Forster Square train was struck by a stone that smashed the front headlight.

The 5.37pm Leeds to Ilkley Northern Rail service had its windscreen shattered by a stone.

The 5.45pm Leeds to Bradford Forster Square train was struck by a stone that hit a side panel and broke the outer skin of a window.

A British Transport Police spokesman said: "There is a rise in instances of trespassing, stone throwing and placing obstructions on the railway line during the holiday period."

Officers are reassuring train travellers that they have stepped up patrols in a number of targeted areas to coincide with the school holiday.

British Transport Police Schools liaison officer PC Steve Wareing said: "Parents are often unaware that their child is trespassing on the railway. If your child is coming home covered in grime or dust, ask them where they have been playing and remind them of the dangers.

"The railway is not a playground and the reality is risking being hit by 25,000 volts of electricity and trains travelling at speeds of up to 100mph.

"A train can't swerve to miss someone in its path. The railways are not a playground and can be a dangerous environment.

"Anyone caught trespassing can face a maximum £1,000 fine."

BTP works closely with train operating companies, including Northern, to educate young people about the dangers of trespassing. Network Rail regularly promotes its "No Messin Campaign" aimed at educating young people about the risks and dangers of straying on to the railways.

BTP is appealling to residents who see children trespassing or stone-throwing on or near the railways to contact them on Freefone 0800 405040 or Crimestoppers anonymously on 0845 555 111.