Philadelphia police have launched an internal investigation after a teenager allegedly suffered a ruptured testicle during a pat-down.

Darrin Manning, 16, was with a group of teammates on their way to an after-school basketball game at 15th and Girard Streets when he was stopped by police officers.

Manning says he was handcuffed and patted down by a female police officer, who grabbed and pulled his genitals. He underwent emergency surgery the following day.

Injured: The day after his arrest, Darrin Manning had emergency surgery on his genitals stemming from what he says was an assault by a female officer

Manning, a straight-A student at Mathematics, Civics & Sciences Charter School, says that he was stopped for no reason.

'I didn't deserve to be wrongly stopped. They didn't - they didn't tell me what I did,' Manning told Fox 29.

While he was handcuffed, Manning says, one of the officers assaulted him.

'She patted me down again, and then I felt her reach, and she grabbed my butt. And then she grabbed and squeezed again and pulled down. And that's when I heard something pop, like I felt it pop,' Manning said.

He spent eight hours in jail after the alleged attack, but police say he never reported any injuries.

The next night, Manning spent the night at the Children's Hospital of Philadelphia where he underwent emergency surgery on his genitals, hospital records show.

Doctors say he may never be able to father children.

Serious injury: A week after his operated Manning was still in pain and unable to walk

School sports: Manning was in his uniform on his way to play a basketball game with fellow students from Mathematics, Civics and Charter School when the alleged assault happened at 15th and Girard Streets

According to Philly.com, the police report states that Manning and his friends began running away from an approaching cop.

But then Manning stopped: 'I didn't do anything wrong,' he said.

Officer Thomas Purcell accosted the teen. The report says Manning struck the officer three times and ripped off his radio. Purcell called for assistance.

Manning says he was handcuffed, roughed up and then patted down by a female officer who he says caused his injury.

'I blame myself,' Coney told Philly.com, crying. 'I taught my son to respect cops, not to fear them. Maybe if he was afraid, he would have run like the other boys and he would have been OK.'

A witness told Philly.com that she watched the confrontation, intrigued because of the excessive force.

'There were all these cops and cops cars, and one kid,' she said.

Horrified: Ikea Coney, Manning's mother, says doctors told her to press charges against whoever had injured her son

Manning is facing charges of aggravated assault and resisting arrest.

He and his mother, Ikea Coney, have retained the services of an attorney.

'He's in shock,' attorney Lewis Small said. 'It's such a tragedy to happen to, you know, a young man like this who's going to be scarred, whether it's physically scarred, which is a possibility, but certainly mentally scarred his entire life.'

Coney says doctors told her that her son may never be able to have a family of his own.

'The doctor told me, "You need to press charges," and that just alarmed me,' Coney told Fox 29.

Philadelphia Police Commissioner Charles Ramsey said yesterday that Manning and his mother haven't filed a complaint nor spoken with the Internal Affairs division about the incident.

Exemplary student: Manning is a straight-A student who has never been in trouble at school, says the Mathematics, Civics and Charter School school founder Veronica Joyner

'We want to know what happened,' Ramsey said today.  'This is a young man with no history in terms of negative contact with the law.  My understanding is he is a good student.  I don’t know what took place, and I’m not in a position to say at this point in time because I don’t have all the facts.'

According to CBS Philadelphia, Ramsey showed reporters video of the incident, but the coverage was unclear because the camera was set to pan across the intersection every 10 seconds.

Ramsey has pulled one female officer from the street until Internal Affairs completes its investigation.  According to CBS, it doesn't look like she was even involved in the struggle with they boy from footage the camera caught, but was keeping passersby from getting too close to the tussle.

Police can't comment on the case because it's now an internal investigation.

Supporters of Darrin Manning are planning a rally on January 23 to protest against excessive use of force and to demand the female officer who allegedly assaulted the teen be fired.