A Myanmar court has sentenced a New Zealand bar manager and his two business associates to two years and six months in prison for insulting Buddhism.

The trio was convicted on Tuesday for posting a flyer on social media that showed a psychedelic depiction of Buddha wearing headphones.

Phillip Blackwood, 32, Tun Thurein, 40, and Htut Ko Ko Lwin, 26, were given two years for insulting religion and six months for disobeying an order from a public servant.

The trial of V Gastro Bar manager Phillip Blackwood, bar owner Tun Thurein and employee Htut Ko Ko Lwin came as the predominantly Buddhist nation grapples with a surge of religious nationalism, including violence against members of the minority Muslim community.

The three were arrested in December after the image was used on Facebook to promote the tapas bar and lounge, and sparked outrage on social media.

The online ad was removed and an apology was posted, but the three men were detained in Myanmar's notorious Insein prison.

'Freedom under threat'

Phil Robertson, deputy Asia director of Human Rights Watch said that, while the three men acted in a culturally insensitive way, they should not be sent to prison.

"It's clear that the authorities have decided to throw the book at them, and make an example of them, and in the process, have kow-towed to pressure from the extremist Buddhist groups, like the Ma Ba Tha," Robertson told Al Jazeera's Florence Looi, who is reporting from Myanmar.

In a statement sent to Al Jazeera, Amnesty International demanded that the conviction "be overturned immediately," adding that the case "is a chilling indication of the growing climate of religious intolerance in the country."

Judge Ye Lwin said that although Blackwood posted an apology, he had "intentionally plotted to insult religious belief" when he uploaded the photo.

He added that it was "unreasonable only to blame the foreigner" when explaining the guilty verdicts for Tun Thurein and Htut Ko Ko Lwin.

Blackwood's parents, however, told Fairfax Media from their New Zealand home that they were shocked by the decision.

"We hoped common sense would prevail and he would be found not guilty because it was not a malicious or intentional act," Brian Blackwood, Phillip's father, said.

About half a dozen monks and Buddhist nationalists gathered outside the Yangon court to hear the verdict.

After the sentencing, Blackwood told reporters as he was getting into a police lorry that he would appeal.