This is the dramatic moment a quick-thinking instructor tackled a customer pointing a gun at his own head at a shooting range in Thailand.

The trainer, Nanthawat Janjana, 31, was watching over customers firing at targets in the practice grounds in Chiang Mai province on October 2.

All was seemingly well inside the establishment before the man, Sirichai, 65, pointed a gun at his own temple in an apparent suicide attempt.

Before the distraught local could pull the trigger, however, Nanthawat sprung into action to wrest the firearm from his hands.

CCTV footage shows the pair's tense scuffle on the floor, with another employee jumping over the counter to pin down Sirichai.

Nanthawat said: 'I found it strange when he asked for only four bullets when normally, people will have an entire box.

'Once he finished firing those four bullets, he pulled two more out of his pocket and said to me those were ammunition left over from his home. After that, he told me to step back.'

The heroic employee added that he allowed the villager to rent a gun as he did not seem unwell when they were talking earlier, nor did he appear inebriated.

Another security video taken near the building's entrance shows Sirichai alighting from his motorcycle with his son and pulling the teenager in for an emotional embrace, seemingly bidding their final goodbyes.

Chang Phueak police arrived soon after the incident and interviewed Sirichai's son.

An officer said: 'The man's son admitted that he was aware of his father's plan to take his own life today.'

Citing the boy's testimony, investigators said Sirichai had fallen into despair after his dormitory business failed due to the Covid-19 pandemic.

He has since been taken to the Nakhon Ping Hospital in Chiang Mai for treatment.

Nanthawat said: 'I would like this case to be a reminder to everyone. If you're thinking of doing something like this, think also about the people you would be leaving behind. They are the ones who would be troubled. Talk to someone and get help.'