© AFP / Romeo Gacad
A man, thought to be a Buddhist monk, has been arrested over a horrific slashing attack on a street vendor in Bangkok. He reportedly attacked the seller to prove that his wares - lucky necklaces - were no protection from danger.

The Chinatown street vendor told the 'monk' that the necklaces were lucky amulets to protect the wearer from harm when the latter suddenly pulled a huge knife from his robes and stabbed him, according to witnesses.

A fast-acting passerby who witnessed the horrific January 18 attack rushed to the street seller's aid and helped to stem the flow of blood from his gruesome injuries. The tourist who jumped into action to assist the wounded man stayed by his side until paramedics arrived.

Police arrested the 54-year-old suspect at the scene without any further altercation, according to local reports.

Officers from Phlap Phla Chai Police Station 2 are investigating the incident and say they uncovered documentation about his ordination but have yet to fully determine if the alleged attacker was indeed a real monk.

They are also waiting to interview the 30-year-old victim once he is well enough to speak with them. The man sustained serious head and neck injuries in the attack and is being treated in intensive care.