Police in New York City have arrested a man after a string of stabbings on the city's subway that left two people dead and two injured.
Rigoberto Lopez is charged with two murders and two attempted murders at stations in Manhattan and Queens.
City police posted a photo of a knife. All of the victims are said to be homeless people.
US media report the suspect, 21 and himself homeless, was arrested wearing blood-soaked clothes.
The four attacks on the A train began on Friday morning:
- In the first assault, a 67-year-old man was stabbed at the 181st Street station in Manhattan, and is now being treated in hospital
- In the evening, a man - believed to be in his 50s - was found dead with knife wounds at Queens' Far Rockaway-Mott Avenue station
- Shortly afterwards, a 44-year-old woman was found in a pool of blood at the 207th Street station in Manhattan. She died in hospital
- And in the early hours of Saturday, a 43-year old man was discovered wounded on a train at the same station
"I'm not going to get into motive, but what I can tell you is they were all unprovoked attacks," NYPD senior officer Brian McGee was quoted as saying by the New York Post.
"The victims had nothing, didn't initiate anything."