Eyewitness Simon Bailey told the M.E.N he got to the scene ‘about 30 seconds’ after it happened.
“I was walking home from work and I heard sirens and police cars going around the corner,” he said. “When I got there behind them, I saw loads of officers on top of a young guy.
“One of the officers was led away by colleagues and he had a large cut to his left cheek and was bleeding. It looked like he had been slashed with a knife.”