An Orpington 15-year-old was "shocked" and "angry" after a police search ended in him needing six stitches in his head.
The incident happened on Saturday (March 1) at around 5pm, as Jason Bermudez was waiting with friends at a bus stop close to Sundridge Park railway station.
Police approached him following up reports of a man armed with a knife at the location.
Jason, of Meadow View, St Paul's Cray, told News Shopper "The police pulled over and a female police officer got out and came over to us.
"She told me to get my hands out of my pockets.
"I got my hands out and she grabbed them and started trying to handcuff them.
"I didn't know what I had done so I started resisting and pulling away.
"A male officer then ran in and pulled me towards him.
"He twisted me around and I hit my head on the post which was holding up the bus stop."
Jason was knocked out by the blow and came around shortly afterwards.
He said: "I don't know how long I was out for but when I woke up my forehead was basically open and there was blood coming down my face.
"There was an ambulance and there were still police around but the officer who had done it to me had gone."
Jason was taken hospital where he received six stitches. Police did not arrest him and no weapon was recovered.
He added: "I didn't know what to think. I was shocked. I wasn't expecting it.
"When I thought about it I was angry."
His father Thomas Bermudez, 42, who used to be a police officer in his native country of Columbia, said: "The police are unprofessional.
"Any country in the world this is a very bad situation.
"He is only 15-years-old. The procedure is not good."
A police spokesman said: "Police were called to Plaistow Lane, Bromley at 4.59pm on Saturday March 1, after reports of a male armed with a knife at the location.
"Officers attended the scene and while attempting to restrain a youth in order to search him, the youth and a police officer fell to the ground.
"The youth sustained a cut to his forehead that required hospital treatment."