Image copyright AFP Image caption Police say 3kg of TNT was used in the blast

The trial of two suspects accused of being behind a bomb attack that killed 20 people in August last year in central Bangkok is under way.

Both suspects are ethnic Chinese Uighurs. They pleaded not guilty to the charges in February, and since then have complained of being tortured.

Hearings have been delayed because of difficulties finding a Uighur interpreter.

The bomb blast occurred at a shrine popular with Chinese and Buddhists.

Uighurs - a Turkic-speaking Muslim minority in the far west of China, complain of cultural and religious persecution at the hands of the Beijing authorities.

The Chinese embassy has now provided interpreters but the defendants have objected.

Both men complained of being tortured while in military custody, but the court has dismissed the complaints.

The two defendants were caught three weeks after the blast but 15 other suspects fled the country.

Police told local media that 3kg of TNT had been stuffed in a pipe inside the shrine and that an electronic circuit suspected to have been used in the attack was found 30m from the scene.

According to official figures at least 123 people had been injured in the attack.

Media playback is unsupported on your device Media caption Dashcam footage captures the moment the bomb exploded near a shrine

A month before the attack the Thai authorities deported more than 100 Uighurs to China - a move that prompted widespread condemnation.

The BBC's Jonathan Head in Bangkok reported at the time that while there were violent elements in the Uighur movement, an attack on this scale outside China would have been unusual.

The explosion was on the Ratchaprasong intersection, which has been the centre of political demonstrations in recent years.

Bangkok Bangkok Bangkok Gaysorn Plaza shopping centre Erawan Shrine Erawan Shrine BTS Skytrain Approximate blast area Ratchaprasong Junction 200m Google Reuters 500 feet THAILAND

Eyewitness accounts of the blast - "There was total chaos"

CCTV footage - captures the moment of the explosion

The Erawan Shrine - popular with locals and tourists

Mobile phone footage captures the blast

'I gave one man CPR' says BBC man