A BUS firm has put up a reward to help catch arsonists who destroyed a double decker bus in Bolton town centre.

First Manchester is offering £500 for information leading to the conviction of the offenders, who left a £100,000 double decker bus wrecked by fire.

Detectives have been studying footage from CCTV security cameras in the hunt for four men they want to speak to in connection with the blaze.

The men are believed to have left the 562 First bus minutes before the fire - which is being treated as arson - swept through the top deck.

Bus driver Leslie Charnock and two passengers fled from the bus seconds before it was engulfed in flames in St George's Road, Bolton, last week.

Detectives investigating the blaze believe it was caused by a burning cigarette that was deliberately wedged into the rear seat on the upper deck.

They want to speak to four men, believed to be in their late teens or early 20s, who were on the top deck of the bus and got off in Breightmet, two miles from the town centre.

The bus was so badly burnt that no forensic examination was possible.

David Doolin, spokesman for First Manchester, said: "These offenders have got to be caught. They have left a double decker bus a write-off.

"There is £500 on the table from the company for information leading to the conviction of the people responsible."

Police have confirmed that no type of accelerant was used in the arson attack.

Det Con Liz Hopkinson, of Bolton CID, said: "I am keen to speak to the four people to assist with our investigation.

"They may not be involved in the arson attack, so if they come forward it would help to eliminate them from our inquiries.The driver remembers that they got on the bus and paid using weekly bus tickets."

Officers are studying CCTV cameras from shops and firms in the Breightmet area.

Firefighters brought the fierce blaze under control within 20 minutes after the alarm was raised by the driver at 2.25pm.

Crowds gathered to watch as the flames spread dangerously close to Debenhams department store.

The foam and plastic from the seats caused the fire to spread rapidly though the bus.

Anyone with information about the arson attack is asked to contact Det Con Hopkinson at Bolton CID on 0161 856 5740.