Witnesses have spoken of their horror and disbelief after a British woman in her 60s was stabbed and decapitated in a Tenerife supermarket.

People reported seeing the killer run out of a supermarket in Los Cristianos on the Spanish resort island, carrying the victim's head, before being tackled by security guards.

Reports named the suspect as Deyan Valentinov, who is believed to be a homeless Bulgarian man with a police record. He is understood to have obtained a knife from inside the store to launch the attack.

Colin Kirby of Tenerifemagazine.com, who was in the supermarket at the time, said: "There were people shouting. There was a Hispanic-looking guy walking behind me, looking very scruffy, muttering to himself, carrying what I thought was a joke head by the hair. The blood - it just made me think Clash Of The Titans. I thought, 'The guy's a nutter, it's a joke'."

He added: "The security guards came out, they chased him across the road. By this time he's empty-handed. They got him on the other side of the road, just by the cultural centre. A couple of people tried to get him, they flattened him, got him on the ground."

Mr Kirby said he had spoken to an English couple who were in the shop at around 10.30am on Friday when the incident happened. "They said this guy just walked in, pulled a big knife and started stabbing at her," he said.

Christina Perez, a legal representative at a nearby court, said a group of lawyers saw the man sprinting out of the Chinese store, carrying the head.

"They saw the man running out of the supermarket with the head in his hands," she said. "A security man from the complex ran after him and jumped on to him so he fell, and then he threw the head on to the road."

Ms Perez, 38, said her frightened colleagues darted indoors for safety.

"They were shocked. Some of them ran to the office and locked themselves in," she said. "Everybody is shocked. It's a very safe area. You can usually go anywhere you want in the day or at night. This is really not normal."