The company said enough was enough

The move is in response to a spate of attacks on First buses on 3 March which left the company with a �50,000 repair bill.

Fifty bus windows were broken, 14 of those in Summerston, in the city's west end - an area proving to be a vandals' hotspot.

Alan Pert, security manager for First in Glasgow, said he was "disgusted" by the attacks and urged youngsters to consider the safety risks they posed.

'Diverting services'

First has a fleet of 10,000 buses throughout the UK and 1,000 in Glasgow - making it the city's biggest operator.

Company security staff and plain clothes police will board buses in the hope of identifying vandals.

Mr Pert said it would liaise with police in an effort to catch those responsible but warned of service withdrawals if the vandalism continued.

He said: "We would urge them to think seriously about the possible consequences of their actions.

"We are monitoring the situation closely and any more incidents in Summerston will result in us diverting services away from the problem areas after 6pm."

The safety of our passengers and driving staff remains paramount Alan Pert, First security manager

It was not a decision the company took lightly and it regretted any inconvenience caused to passengers, he added.

"However, the safety of our passengers and driving staff remains paramount."

First has approximately 8,000 bus windows broken every year in Glasgow - an average of 23 per night.