A £5,000 reward has been put up in a bid to catch the yobs who left a driver with multiple serious injuries when a 22kg block of masonry smashed through a train window.

Joseph Paxton, of Birmingham, was originally left fighting for his life after the shocking incident, which happened at about 10.45pm on Sunday.

The 56-year-old was rushed to Worcestershire Royal Hospital, where his condition has been upgraded to "stable". He is expected to be allowed back home in the next few days.

A resident alerted emergency services after hearing the driver sound the horn when it came to a stop near to Lyndholm Road, Kidderminster.

British Transport Police now believe the incident took place near to the Offmore Road footbridge, when a large section of a wall containing about five bricks fell onto the freight train, which was travelling at almost 50mph.

CCTV footage showed the window intact as it passed through Kidderminster station. Officers will be handing out flyers in the area in attempts to gather information.

EWS, which operated the services running between Llanwern and Brieley Hill, has offered the substantial reward in attempts to find the culprits.

Pat Daly, the company's director of risk management, said: "This was an appalling attack on a committed and professional driver. We are deeply shocked by this incident and the extent of his injuries.

"It is vital that those involved in this crime are caught and we urge anybody who is aware of any information to contact British Transport Police. Nobody should spend Christmas suffering with injuries like this."

Chief Insp Allan Gregory said: "In the 14 years I have worked here this is by far the most serious route crime I have ever known. The driver could easily have been killed.

"At first, his condition was described as critical, then serious and now, miraculously after this horrendous and shocking incident, he could soon be discharged."

He added because of the size and weight of the block it was possible more than one person could have been involved and a wheelbarrow may have been used to transport the bricks.

Anyone with information should contact British Transport Police on 0800 405040 or Crimestoppers, anonymously, on 0800 555111.