A 46-year-old Spanish man is battling for survival in hospital after a brutal street attack in which an Algerian migrant repeatedly stamped on his head while he lay helpless on the ground.

Shocking mobile phone footage that has gone viral shows the terrifying moment the attacker, identified as 26-year-old Said L., launched an unprovoked assault on Arturo C.P. near Valencia on Friday evening.

The victim, who was already vulnerable with his arm in a cast and waiting for a kidney and pancreas transplant, was left in a critical condition with a severe brain haemorrhage after the sustained stomping.

In the harrowing video, filmed from a nearby car, Arturo can be seen lying on a pedestrian crossing in the San Marcelino neighbourhood as the attacker, dressed in a light top and shorts, repeatedly drives his foot down onto the man’s head with sickening force. Clouds of dust rise with each stamp while bystanders appear to intervene.

Arturo had been visiting his mother when the attack unfolded around 9pm in Calle Ingeniero José Sirera. Witnesses say the Algerian approached him without a word, kicked him in the leg and then continued the assault even after he was completely defenceless on the pavement.

Local police arrested the suspect shortly afterwards. The 26-year-old, who is reported to be living in Spain illegally and has a criminal record, was ordered into provisional prison without bail on attempted homicide charges by a Valencia judge.

Arturo remains in a coma in intensive care. Doctors are monitoring him closely for neurological damage after the violent blows to the head.

The graphic footage has sparked widespread outrage across Spain, with many questioning how such a vicious, random attack could happen in broad daylight on a residential street.

Spanish media report that the suspect was undocumented and had been sleeping in a nearby shack. Early reports incorrectly identified him as Moroccan before it was confirmed he is Algerian.

The case is being treated as a serious attempted murder inquiry given the life-threatening injuries inflicted on the already frail victim.