A Tory MP has been attacked after challenging a man who was vandalising a bus shelter.
Backbencher Stewart Jackson said he tried to make a citizen's arrest after seeing the man smash the glass with a bottle.
But the culprit fled after kicking him in the chest.
Mr Jackson, who had been shopping with his wife and daughter in his Peterborough constituency, posted about the incident on Twitter.
"Had set to with violent thug kicking in bus shelter in Broadway & suffered kick in side for pains," he wrote.
He told the BBC: "I thought any of the shards could have injured a woman or a child so I tried to make a citizen's arrest.
"He squared up to me and threw a few blows which missed but he swung a kick which made contact but I was not badly injured. He then ran away and my wife called the police."
Cambridgeshire Police said a 20-year-old man was detained after officers were called to the scene at 3.10pm on Saturday.
Mr Jackson told the Press Association: "I was walking past and couldn't just ignore it... That's when I put my shopping down and went on up and said, 'You can't do that.'"
He added: "I just felt, I live there, it is my city, it is my constituency. When you tolerate that the next thing is that they are smashing up people's faces."