Hundreds have protested in the Myanmar city of Yangon after two workers from the country were sentenced to death for killing two British packpackers on a Thai island.

Demonstrators, including monks, gathered outside Thailand's embassy after Zaw Lin and Win Zaw Tun were convicted for the murders of David Miller, 24, and Hannah Witheridge, 23.

The British holidaymakers were found battered on a beach on the southern Thai diving resort of Koh Tao in September last year.

Miss Witheridge had been raped.

During the trial the defence accused the police of bungling their investigation and using the men as scapegoats - a charge authorities deny.

Police have been accused of obtaining confessions - eventually retracted - through torture. 

Protesters held signs with English slogans such as "Save Myanmar Poor Boys" and "Free Our Innocent Citizens".

Others held up pictures of Thailand's King Bhumibol Adulyadej, saying they were appealing to him for clemency.

"This is just discrimination against us," demonstrator Min Thein Khaing told AFP.

"There was little evidence, no witnesses and not much DNA evidence but still they got a death sentence . It's unfair."

A police cordon stopped protesters demonstrating opposite the embassy itself, confining them to the end of the street instead.

Meanwhile, Amnesty International has called for a full investigation into claims the suspects were tortured.

Champa Patel, Amnesty International Director for Southeast Asia and the Pacific, said: "The Thai police force has a long and disturbing track record of using torture and other forms of ill-treatment to extract 'confessions'.

"This is far from an isolated case."