Image copyright Getty Images Image caption Philadelphia police say the suspected carjacking happened on Thursday

A couple have been questioned by police and may face charges after a suspected carjacker was beaten by a mob and died in the US city of Philadelphia.

Police say the man who died had tried on Thursday to steal a woman's car with her three young children inside.

The woman's boyfriend, the father of two of the children, managed to chase the car when it got stuck in traffic.

The suspect, 54, was then pulled out of the vehicle and beaten by the boyfriend and some local residents, police say.

The suspected carjacker was unconscious when emergency services arrived at the scene shortly afterwards. He later died in a local hospital.

The couple who were questioned by police are both aged 25. They have not been identified.

"I'm not a fan of street justice," Philadelphia Police Capt Jason Smith was quoted as saying by CBS.

"I think everything should play out through us as it comes to criminal actions," he added.

The city's medical examiner's office is yet to determine how the suspected carjacker died.