A Chinese Uighur accused of planting last year's deadly Bangkok bomb on Tuesday claimed he was being mistreated in custody, shouting "I am human, I am human" as he struggled with guards on his way to a hearing.

Bilal Mohammed, also known as Adem Karadag, and co-defendant Yusufu Mieraili are charged with key roles in the August 2015 bombing of the Erawan shrine in downtown Bangkok that killed 20 people -- mainly ethnic Chinese tourists.

Mohammed, 31, a Chinese citizen from the Uighur ethnic minority, is accused of being the man seen in CCTV footage wearing a yellow T-shirt and placing a backpack at the Erawan shrine moments before the explosion.

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Prosecutors say he was caught a few days later in a Bangkok flat surrounded by explosives.

Mieraili, 26 and also a Chinese Uighur, is accused of delivering the backpack bomb.

The pair deny the bombing charges, although Mieraili has admitted a charge of illegal entry to the country.

Arriving shackled and shaven-headed at the Bangkok court on Tuesday, a visibly distressed Mohammed shouted his complaints to reporters in his native Uighur and then in English.


In February 2016, the Uighur pair denied the charges

The drama continued in the courtroom where a sobbing Mohammed spoke through a Uighur translator to accuse his Thai captors of beating him and denying him halal food.

"I can not eat, I am laughed at when I pray," he added.

Mohammed's lawyer has previously accused the Thai police of forcing confessions from his client. An initial admission of guilt was later retracted.

Police rubbish the torture allegations and say the evidence against the pair is watertight including forensics, CCTV footage and mobile phone data.

They are however still seeking a number of other suspects -- many of whom, including the alleged mastermind, are believed to be overseas.

A convincing motive is yet to be established for an attack that dented Thailand's key tourist industry and spread fear through a politically febrile country that is under military rule.

But speculation of a link to Thailand's deportation of 109 Uighur migrants to China a month before the bombing has refused to die down.

The Uighurs are a mainly Muslim minority who face persecution and restrictions on worship in their northwestern Chinese homeland, forcing many to attempt to flee.

Thai authorities have rejected the theory that the bomb was a revenge attack for the Uighur deportations, instead insisting the unprecedented attack on the capital was in retaliation for a crackdown on a people-smuggling gang.