Subway Attack: Suspect Held By US Police

Police investigating a horrific attack on a woman on the Philadelphia subway have arrested a man.

Surveillance video shows the 23-year-old woman being viciously punched and then dragged across the platform.

She is then pushed onto the railway track at the station in the city's Chinatown neighbourhood.

The attack happened around 3.30pm on Tuesday, after the suspect initially approached the victim and asked for a light.

The woman miraculously suffered only cuts and bruises and managed to climb off the tracks onto the opposite platform.

Police say they arrested the man around 2.30pm on Thursday, identifying him by his distinctive, multicoloured jacket with an image of the Taj Mahal on the back. 

"It was so distinct that we tried to keep the description of that jacket in law-enforcement circles, because it was our best lead on clearing this," transport police Chief Thomas Nestel said during a news conference.

Officers said a mobile phone belonging to the woman was also recovered.

However the police decision to keep quiet about the attack was criticised by some for leaving a potentially dangerous suspect at large with no public warning.

Unlike two recent fatal subway attacks in New York, the woman was not thrown in front of an approaching train, Chief Nestel said.

However, he advised subway passengers to "always be aware of their surroundings" and avoid standing close to the edge of the platform.