Police launched a huge manhunt after a man was stabbed multiple times by a stranger on a train - leaving him fighting for his life.

Roberto Gaspar, 25, was checking his phone on the subway in Queens, New York on Sunday night when an attacker suddenly struck. The suspect “stabbed him multiple times in the back with an unknown sharp object,” the NYPD said, before fleeing. Gaspar was rushed to hospital in critical condition. CCTV released by police show the suspect, dressed in a black hoodie, smiling as he walks down the train carriage. He is described as slim, light-skinned and aged between 20 and 25.

“He is serious, he can’t talk,” his friend Tomas Calel told the New York Post. “He’s in the ICU. He’s hooked up to machines.”

Gaspar, who works 10-hour long shifts at a Manhattan restaurant to send money home to his family in Guatemala, never saw his attacker. “I feel bad for him,” Mr Calel said. “He didn’t see anything. He doesn’t know who did it.”