Bangkok bomb: Video shows man slipping off rucksack inside shrine and calmly walking away – minutes before explosion

The man matches the description of a suspect sought by Thai authorities

The man in a yellow T-shirt can be seen slipping the rucksack from his back

CCTV footage has emerged showing the moment a man slips off a rucksack just outside the Bangkok shrine where a pipe bomb killed 20 people – 20 minutes before the explosion.

The footage, obtained by a Thai news agency Thairath, shows an unidentified man – wearing a yellow T-shirt – slip off a black rucksack on a bench next to the Erawan Hindu Shrine, in central Bangkok.

A timestamp, captured on the low quality footage, shows the time and date as 6.40pm on 17 August – just 20 minutes before the bomb is believed to have detonated.

At least 20 people died in the bomb and as many as 123 are believed to be in hospital after being injured by the attack.

It follows the release of a description of a man by Bangkok authorities of a man wanted in connection to the bombing. CCTV stills of man matching that description have been widely shared online.

The images show a man in a yellow T-shirt. In two of the images he appears to be wearing a black rucksack, while in two later images he appears to be without the rucksack.

The attack on the popular shrine in the centre of the bustling city has been labelled the “worst” ever enduring by the Thai Prime Minister Prayuth Chan-Ocha.

The defence minister has said authorities had no prior intelligence about the attack but that they were now closing the net on the suspects.

"Today we have seen the closed-circuit footage, we saw some suspects, but it wasn't clear," defence minister Prayuth Wongsuwan told reporters. "We have to find them first."