An off-duty bus manager jumped on to a bus and tackled a knifeman as he threatened a passenger with a 12-inch knife.

Les Marsh has been praised for his "astonishing bravery" after wrestling the kitchen knife from the man.

Mr Marsh was travelling in his car when he saw two male passengers arguing on the number five bus to Blackbird Leys, Oxford, shortly before midnight on Wednesday.

He followed as the driver pulled into a bus-stop near The Original Swan pub in Oxford Road, Cowley, then leaped on board and grabbed the knife away from one of the men as the other passengers were evacuated. Armed police officers were sent to deal with the situation, but by the time they arrived Mr Marsh had disarmed the knifeman and had hold of him on the bus.

The other passenger is thought to have suffered a cut to his hand, but Mr Marsh has been commended for acting quickly to prevent further injury.

The bus driver used his radio to alert Oxford Bus Company's depot, in Garsington Road, Oxford, as the incident unfolded, and another member of staff, Mick Gifford, was sent to help. He helped Mr Marsh, who works for Oxford Bus Company, keep hold of the knifeman until police arrived.

Nigel Eggleton, commercial manager at the Oxford Bus Company, said: "This was an astonishing act of bravery from Mr Marsh, who showed great presence of mind. He and the other employee did a grand job, and a difficult situation was resolved."

Mr Eggleton added: "This provides further evidence of the usefulness of CCTV cameras on buses, but these incidents are incredibly rare, considering the number of passengers we carry."

He said CCTV footage of the incident had been handed to police.

Thames Valley Police said a man was arrested and bailed on suspicion of possession of an offensive weapon, and affray. As reported in the Oxford Mail, the Oxford Bus Company announced last month that it had fitted CCTV cameras to all 160 buses in its fleet at a cost of £500,000.

Some buses now have nine different cameras on board and managers believe they deter the majority of crimes from taking place.

Last month, the company released CCTV footage showing a gunman holding up the driver of a bus on the Blackbird Leys estate.

The driver laughed off the attack and pulled away, before the attacker could board the bus last January.

The company passed the footage to the police, and the offender, who was using a replica pistol, was jailed for seven years.