A couple on holiday in Thailand were left rolling on the ground while covered in flames after being SET ALIGHT by a crazed local.

Ong Yik Leong, 26, and Gan Xiao Zhen, 27, were waiting outside a supermarket when a passerby doused them with paint thinner on Thursday evening.

The pair, from Malaysia, tried to run away but were chased by Thai man Warakorn Phabthaisong, 30, who sparked the flammable liquid with his lighter.

Horrific footage shows Gan screaming in agony as she is engulfed in fire. She rolled around on the pavement before onlookers poured water on her, extinguishing the flames.

Medics arrived and administered first aid. The couple were then rushed to a hospital and are now out of danger.

Police detained Warakorn at the scene near the Big C Supercenter store on Ratchadamri Road.

An officer was seen slapping him before furious locals beat him as he was being cuffed. Officers searched his bag and found clothes, personal items, and the bottle of paint thinner used in the alleged attack.

He was taken to the Lumphini district police station for questioning.

Police Superintendent Yingyot Suwanno said: 'The perpetrator confessed to the crime and said he had no prior grudge against the couple. He said he committed the crime due to stress over his joblessness and lack of income.

'He was previously a boxer who became a security guard, but he was recently fired. He has been trying to find employment but has not been hired. He says he has not eaten, which contributed to his severe stress.'

The police boss added that he has ordered investigators to proceed with assault charges. Social welfare workers will be joining the investigation to discuss assistance measures, he said.

Authorities said the two Malaysian tourists are in stable condition and will be summoned to give their statements after recovering.