A man who leapt to the defence of a pedestrian during an unprovoked roadside attack has been hailed a hero.

When Russel Sampson saw a van driver punching a man on the side of a road in Bladon, near Woodstock, his first instinct was to stop to help.

But Mr Sampson, 28, got more than he bargained for when he intervened - as the attacker then turned on him.

It was one of a series of unprovoked attacks on pedestrians and cyclists in Oxfordshire on Sunday, August 10.

One victim, a 57-year-old man from the West Midlands, was walking to Winston Churchill's grave with his wife when the incident happened.

A 42-year-old man from the Princes Risborough area was detained under the Mental Health Act, but no charges have been brought against him.

Mr Sampson was on his way to meet his wife Emma in Long Hanborough when he witnessed the attack. He said: "I was driving along and I couldn't believe what I was seeing.

"I saw the man being repeatedly punched while a woman frantically tried to pull the attacker away from him.

"I parked up, thinking initially it was a road rage attack, and I started shouting at the van driver to leave the man alone.

"I'm quite a big guy - I'm 6ft 2in - so I expected him to stop punching when he saw me approaching, but he started walking towards me, saying 'fight me'.

"I put my hands up to make it clear I was surrendering and a fight was the last thing I wanted, but he continued squaring up to me and assaulted me."

Mr Sampson said the attacker fled when he took pictures of the man's van using his mobile phone.

Mrs Sampson, who lives in Daventry with her husband, said: "What Russel did was very brave.

"So many others drove past and did nothing, while Russel put himself at risk to try to help. He was heroic."

Mr Sampson said: "It was very much a case of seeing someone in trouble and trying to help them.

"I couldn't drive by and see someone getting attacked without trying to help. I was shocked to see the number of people do just that."

In separate incidents, a 17-year-old boy was punched in the face in Bloxham, a cyclist was punched and kicked in Kidlington, a pedestrian was punched in the head in Woodstock, and a 45-year-old man and his wife were assaulted in Enstone.