A gang of youths ambushed a school bus with 30 pupils on board and hurled a brick through a window yesterday. A child sitting next to the window narrowly escaped injury.

The bus was taking pupils from Yorkshire Martyrs Collegiate School, Westgate Hill, home when the gang halted the bus by pressing the stop button at a pelican crossing.

The company which runs the service may change the route after the attack, at about 3.40pm, in Barkerend Road.

Kath Bonson, joint owner of JAK Travel in Girlington, said it would cost about £750 to replace the smashed window. JAK Travel takes children from the school to Haworth Road.

"There has been several incidents in recent weeks, but this is the first time a window has been smashed," she said.

"The gang press the button and ambush the bus. Sometimes rubbish bags are put in the road to stop the bus."

Bricks, stones and fruit have been hurled at buses - in one instance a youth boarded a bus, grabbed a microphone and fled. "It seems these youngsters are deliberately targeting our service," said Mrs Bonson. "Our drivers are not happy and we cannot allow it to continue."

An extra person was due to travel on the bus tonight in an attempt to identify the vandals.

Driver David Stoyles, who called for police on his mobile phone yesterday, said: "Some of the children were quite scared. This brick went very close to me and if it had come through my window the bus could have crashed. The drivers are very wary about going down Barkerend Road at the moment."

Yorkshire Martyrs' deputy head Paul Rowen said: "We are obviously concerned about this. It is one of the most serious incidents I have come across in eight years here.

"A brick smashing a window could have horrific consequences. I also understand this is happening to other school buses in that area."

Mr Rowen urged anyone who saw the incident to contact the police.

A West Yorkshire Police spokesman said the crime was being investigated.

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