TRAIN bosses have warned people not to treat railway lines as a playground after a carriage window was smashed by a missile.

Passengers on the York to Scarborough service were showered with glass when an object was thrown at a train at Strensall.

British Transport Police said today they did not know exactly what had been thrown at the train, but believed it had probably been a stone.

Lawrence Greenwood, 68, from Bridlington, was sitting next to the carriage window when the window smashed all over himself and his wife, Gillian.

He said: "I heard a noise and looked up. It looked like water. It spread the glass everywhere - a young fellow sitting at the table on the other side of the carriage dived out of the way."

Mr Greenwood escaped the incident with a small cut on his hand, but British Transport Police today said the consequences could have been far worse.

Claire Wright, of train company First Transpennine Express, said: "Our windows are toughened and designed to minimize shattering so luckily no-one was seriously injured.

"However, people need to realise that when they throw objects at trains, they are aiming at people and this is extremely dangerous.

"There is no justification for this kind of behaviour and the railway should not be used as a playground."

The incident happened as the cross-country train from Liverpool Lime Street sped through Strensall on Monday at 7.10pm.

PC Nick Storey, who is based at York station, said the incident was "shocking".

He said: "Police condemn any sort of behaviour of this kind. Throwing a stone at a train window - it could potentially go straight through and hit someone on the head - they could have been very seriously or fatally injured.

British Transport Police officers scoured the area around the track at Strensall to see if they could find the culprits, but there was no sign of them.

PC Storey said although incidents of this type were by no means unheard of, it was very unusual for a train to be targeted in this way in the Strensall area.

He urged members of the public who had any information to telephone himself or PC Steve Duck on 0800 405040, quoting incident number 493 from August 15.

Mr Greenwood said train officials ushered passengers out of the carriage, re-seating him and his wife in the first class compartment.

He said: "We were talking about it afterwards, and realised how lucky we were."

Updated: 11:36 Thursday, August 18, 2005