The Koh Samui Provincial Court on Thursday found Zaw Lin and Wai Phyo guilty of the murder of David Miller and the rape and murder of Hannah Witheridge on Koh Tao in September last year, a verdict defence lawyers have vowed to appeal.
The handling of the high-profile case by Thai police has drawn significant controversy, with the accused pair alleging they were tortured into a confession and the defense team contending key evidence was mishandled.
Protesters, including Buddhist monks, congregated outside the Thai Embassy in Rangoon from around 10.30am, with numbers swelling over the next few hours.
Police erected barbed wire barricades on Thursday ahead of a smaller demonstration and on Friday, the road in front of the embassy was blocked where protesters gathered with placards and chants demanding justice.
The two accused migrants are both Arakanese and many ethnic Arakanese joined the protest on Friday.