BBC Radio 4 presenter Eddie Mair has revealed how he was attacked by a gang on a bus in London.

Mr Mair said he was too ashamed to report the incident, which happened in December, to police.

The 52-year-old was left with bruising to his head after being struck by one of a group of three youths on bikes who had encircled him at a bus stop.

Writing in the Sunday Times, he said: "I felt I may have been in some way responsible for what happened."

Mr Mair, who presents the PM programme, expressed sympathy for comedian Michael McIntryre, who was robbed by two men on a moped who smashed his car windows.

His own attack took place as he was returning home from dinner with friends in London.

A gang of youths on their bikes surrounded him as he walked to a bus stop, with one lifting his front wheel close to the presenter's face.

Told no one

Mr Mair said he tried to film their intimidating behaviour, but their faces were hidden by their hoodies.

As he stepped onto the bus, one of them struck him on the side of the head, leaving a large bruise above his right ear.

Passengers helped and offered to call the police, he said, although the driver offered no help - but "I just wanted to get home".

"I told no one, least of all the police. Not my family or friends. Not work colleagues. I felt shame. I felt I may have been in some way responsible for what happened," he said, adding that he wondered if his video recording had goaded them.

"For weeks, every time the local paper reported an assault, I believed that I had contributed to it. More shame," he said.

He eventually reported the assault before he left for a trip to South America, but officers were unable to identify the attackers from his video.

Police told him that reporting the crime earlier may have helped, because CCTV imagery would have been available for up to a month.

Mr Mair, who observed ironically that being affected by crime made him "on trend" for once, also had his bag stolen in a mugging in South America.