A gang of teenagers was arrested for allegedly throwing a Molotov cocktail at an innocent couple they mistook for rival gang members in Thailand.

The thugs were roaming the roads before dawn when they encountered the victims Thanakorn Pangsen and his girlfriend Worakarn Petchkui, both in their 20s, riding in front of a store on Soi Photisan in Pattaya on March 18.

Shocking CCTV footage shows how the suspects hurled the firebomb at the couple as they crossed paths, igniting their screams and leaving the covered in flames before speeding away.

Thanakorn and Worakarn both suffered serious burns and were rushed to the hospital. They told police they did not know their attackers.

Following the assault, Pattaya Police Chief Colonel Thanapong Photi and forensic police visited the scene to collect evidence and discovered traces of oil and blood on the road. They said the smell from the flaming cocktail indicated it oil-based.

Horrified bystander Ploy, 21, said: 'A group of six to seven teenagers on four motorcycles drove together from South Pattaya before separating at the North Pattaya intersection. The suspects turned at the alley and threw the Molotov cocktail at the victims.'

Police announced on March 19 that they had arrested the suspects, an unnamed Cambodian national, 17, and Mew Chamlongrak, 18, who was o the bike with him. Also detained were six of their friends believed to have been involved in the attack.

The Cambodian teen admitted the attack and allegedly told police that he was threatened by rival thugs with a gun.

He said swore to take revenge on them but mistook the couple for his targets as they were both riding the same type of motorcycle. He only learned on the news later on that he had hurt the wrong people.

Mew, who was arrested at his house, also reportedly confessed to being the other half of the duo.

Neither of them had any prior criminal records, cops said.

They added the thugs had learned to make a Molotov cocktail online, by buying the precursors through an online store and following internet tutorials.

Colonel Thanapong Photi said: 'The gang has been caught and removed from the streets. Medical reports have been receive from the doctors that show the victims suffered serious injuries.'

Police said the youth have been charged with jointly causing bodily harm and for violating the Firearms and Explosives Act by possessing an illegal explosive.