This is the bizarre moment a cyclist licked a bridge handrail while carrying a sign that read 'I have covid-19'.

Onlookers were baffled when they saw a middle-aged man park his bicycle on the footbridge and bent down to lick the steel that pedestrians touch in Chiang Mai, Thailand last Friday (April 10).

Resident, Maple Runthiwa, said she was driving with her family waiting for a red light to turn green when she saw him do it.

She said: "First, I saw from the rear view mirror that he was licking his arm so I was curious. I noticed a sign in front of his bicycle a sign that said 'I have Covid-19'.

"Then he parked and licked the handrail. I was so scared that he might walk to me and lick my car, so when the light turned green I rushed from there to the police."

The terrified driver later showed the footage to the police, worrying that the old man might actually have covid-19.

Officers investigated and found out that he is a 40-year-old man living alone nearby the scene.

They went to the man's registered address and arrested him before taking him to a hospital nearby to take a coronavirus test.

The bridge was also disinfected by cleaners after the incident was reported to the authorities.

Police said the man, who was not named, was arrested and taken to the Suan Prung Psychiatric Hospital in Chiang Mai for a mental health assessment.