Mexico fan is left with blood pouring after being stabbed during Gold Cup match

Police are hunting a man suspected of stabbing a fellow Mexico fan - and leaving him in a critical condition - after sickening violence broke out in the stands during the country's Gold Cup clash with Qatar.

The victim was left with blood pouring down his face and chest, while some stairwells were painted crimson, as the violence escalated at Levi's Stadium in Santa Clara.

Grim video footage shows around a dozen Mexico supporters fighting among themselves at the 1-0 defeat by Qatar on Sunday night when a man approaches the brawl, brandishing what appears to be a knife over his head. He thrusts it into the group of fans before being bundled to the floor.

As the fight continues, the victim staggers along the gangway and slumps into a seat, removing his shirt and noticing blood seeping down his chest.

Police say he remains in a critical but stable condition.

According to eye-witnesses, the fight among supporters lasted around 10 minutes, with the fan using water and his Mexico jersey to try and stem the bleeding from near his shoulder.

Police have already identified a suspect - and another person of interest - and are asking the public to help track them down.

The suspected knifeman is described as being between 25 and 35 years old, with short, dark hair and a thin mustache and beard.

He was last seen wearing a green Mexico jersey and police say he fled the area after the stabbing.

The person of interest, meanwhile, was described as a woman with dark hair and wearing a similar Mexico jersey.

Santa Clara police is urging anyone who recognizes the pair to contact them and not try to apprehend them.

Supporters filmed the fight which saw punches being traded, drinks being thrown, stairs covered in blood, supporters knocked to the floor and others being dragged away before police arrived on the scene.

One clip then pans to show the victim with blood pouring down his face and chest and a large open wound near his neck.

He could be seen pouring water on to the gash before using his Mexico jersey to try and stem the bleeding, while panicked fans appear to point police towards the knifeman.

The victim was then led away by officers en route to hospital, with witnesses later accusing security of being 'lax' and not checking bags.

In a joint statement from Levi’s Stadium and CONCACAF they said 'ensuring the safety of our guests is our highest priority.'

They added that they’re cooperating with law enforcement and wish the victim a swift recovery.

Anyone with information is asked to contact Detective Sergeant Doug Gerbrandt at 408-615-4823. People can also send an anonymous message to 408-615-4847.