Terrifying video shows moment crazed attacker stabbed homeless man in broad daylight in front of helpless police officers

A crazed psychopath wearing a blood-stained eye patch stabs a homeless person in the neck repeatedly as young children gape in horror and stunned police officers, with guns drawn, stand by helplessly.

The shocking incident, which took place on a busy street in front of approximately 20 bystanders at around midday, was captured on a mobile phone camera.

According to witnesses, the attacker caught sight of the homeless man, who was pushing a shopping trolley, and rushed over to confront him over an unpaid debt.

Vicious: A maniac attacks a homeless man on the streets of Harlem stabbing him repeatedly in the neck as a police officer watches on helplessly

Stepping in: Around 20 bystanders including young children watched as an officer finally managed to haul the attacker off his victim by the waistband

As stunned onlookers, including young toddlers and their nannies, watched the crazed man wrestled the homeless man to the ground in front of a synagogue and drew a knife from his pocket.

As he begun to stab the man in the neck around a dozen police officers from the nearby 23rd Precinct stationhouse arrived at the scene.

They drew their handguns and ordered the man to drop the knife but he simply ignored them and continued with the brutal attack. 

One bystander can be heard screaming: 'Hit him , hit him with something, he's stabbing him.'  

Aftermath: As the crazed attacker is restrained, his victim, bloody and battered, calls out for help

Eventually a police officer manages to grab the attacker by the back of his trousers and haul him off the victim.

One witness described the brutal attack to the New York Daily Post saying: 'He just literally pulls out a pocket knife and starts stabbing the man in the neck like a couple of times.

'He just kept saying, 'You owe me money! You owe me money.'

The incident happened in Harlem  on Lexington Ave. and E. 103rd St. close to 103rd street subway station. 

The officers were praised for showing restraint and not firing on the subject.

Police have declined to comment on the attack. The condition of the victim, who remained fully conscious throughout the horrifying ordeal, is not known.

The names of the victim and suspects were not released.