On his Facebook page, “Joe Nuttorn” – full name Nuttorn Pityaratstian – a scholar at the Department of Psychiatry of Chulalongkorn University’s Faculty of Medicine, who is currently studying in the United Kingdom, described the terrifying moments as he and his kids were leaving the scene.

Twenty-two people, including children, were killed and dozens injured when a man detonated a bomb at a pop concert by US star Ariana Grande, in what is Britain’s deadliest terror attack in 12 years.

“I was there [at the arena]. I and my kids left the concert while she sang the last song to catch a train back to Liverpool,” he wrote six hours ago.

“While we were climbing 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 kids out of the concert venue – the Manchester Arena – and said that at that time no one really knew what was happening.

His initial reaction was to wonder whether someone might spray bullets on them, or whether perhaps there had just been a loud noise that had panicked concert-goers.

“We were very confused and quickly walked to the train station. We saw people 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 realised after hearing news on the train that the incident had indeed been confirmed as a bomb attack, with scores of deaths and injuries.