“Joe Nuttorn” – whose full name is Nuttorn Pityaratstian – described the terrifying moments as he and his children were leaving the scene on his Facebook page.

Twenty-two people, including children, were killed and dozens injured when a bomb exploded at a concert by American teen idol Ariana Grande in Manchester Arena. The attack was Britain’s deadliest in 12 years.

Nuttorn, a scholar at the Department of Psychiatry of Chulalongkorn University’s Faculty of Medicine, who is currently studying in the United Kingdom, said: “I was there [at the arena]. My kids and I left the concert while she sang the last song to catch a train back to Liverpool.

“While we were going down the stairs we heard a loud bang and some people yelled ‘bomb’ and ‘run’, followed by screams,” he posted on Facebook.

He then rushed to get his children out of the arena and said no one knew what was happening at the time.

His initial reaction was to wonder whether someone shoot at them or if concert-goers had been panicked by a loud noise.

“We were very confused and quickly walked to the train station. We saw people who were crying along the road. Sirens of police cars and ambulances were gradually heard [getting] louder,” he said.

On the journey back to Liverpool, he learned that the incident had been confirmed as a bomb attack and there had been scores of deaths and injuries.

There has not been word whether Grande’s concert in Bangkok on August 17 will be affected.

Bec-Tero Entertainment, the organiser of the Bangkok concert, has not commented but an update is expected on the company’s Facebook page.

Foreign Affairs Minister Don Pramudwinai has warned Thais living abroad to be careful as terrorist attacks have taken place in many foreign countries.

He said the ministry had asked the Thai Embassy in the UK to check whether Thais had been affected by the Manchester attack.