A community is in shock after A 17-year-old boy was stabbed to death outside a Tube station. 

Officers were called to Clapham South Tube Station at 4.35pm on Friday, where they found the teenager suffering from a stab wound.

He was taken to a south London hospital, where he died less than an hour later, the Metropolitan Police said.

Charity director Robin Pritchard said he moved through a crowd and saw the victim lying in a pool of blood while someone provided CPR.

The 47-year-old told the Press Association: "I saw the guy on the floor, a pool of blood like he'd been stabbed in the stomach, his clothes were soaked.

"It was strangely calm and quiet. I think everyone was in shock. Lots of kids there from the local college.

"All I really registered were grey tracksuit bottoms which were soaked with a pool of blood coming from his waist like he'd been stabbed in the stomach."

Another witness, who did not want to be named, said he saw "a bunch of guys" shouting and appearing agitated, with one carrying a large knife.

He added that the area is usually noisy after students leave nearby Saint Francis Xavier College.

He said: "I had no idea it was different to any other time the students get a bit noisy, until I saw the knife as I was literally passing them."

Officers are in the process of informing the victim's family, although formal identification has yet to take place.

No arrests have been made so far and inquiries continue.

Surrounding roads and the Tube station have been closed with police remaining on scene.