Abu Dustar Abdulrahman, known as Izan, travelled to Bangladesh the day before attack and later left for Beijing, police say

This article is more than 5 years old

This article is more than 5 years old

The suspected mastermind of a bomb attack in Bangkok last month that killed 20 people travelled to Bangladesh the day before the blast and is now in China, a senior Bangladeshi police officer has said.

The suspect, Abu Dustar Abdulrahman, also known as Izan, gave orders to others to carry out the attack, the worst peacetime bombing in Thailand’s history, Thai police say.

AKM Shahidul Hoque, inspector general of the Bangladesh police, told Reuters that officers had checked his details with the immigration department and confirmed that he had arrived in the country on 16 August and departed on a flight to Beijing on 30 August.

He said police were trying to identify the hotel where Izan stayed while in Bangladesh. China has not commented on the reports.

Thai authorities have been criticised for releasing contradictory information in the days after the attack and speculating about differing motives. No group has claimed responsibility.

A suspected bomber was captured on grainy CCTV footage in a yellow T-shirt leaving a black backpack by a bench minutes before the blast. He has yet to be apprehended or named. On Friday Thai police said the search for him had expanded to Malaysia after fresh information that he may have crossed Thailand’s southern border.

After a lull in the investigation, a man named Yusufu Mierili was arrested last week at the Thai-Cambodian border. Police said his fingerprints had been found on a container of gunpowder at a Bangkok apartment, but they do not believe he is the man in the yellow T-shirt.

Thai police said Mierili identified Izan as playing a key role in the attack and had assigned responsibilities to other members of the group.

Police have suggested the bombing relates to a criminal gang. There is growing speculation in Thailand that the attack is linked to Uighurs, a Muslim minority in western China.

Thailand forcibly returned 109 Uighurs to China in July. The deportations angered the Uighur community and caused an outcry from human rights groups and the UN amid fears they could face persecution and abuse.

Many Uighurs have fled to Thailand in the hope of travelling on to Turkey, which has strong cultural links to the group and has sheltered them for decades.

Thai authorities have suggested at least two of the suspects are Turkish, and a leaked photo, purportedly of Mierili’s passport, suggested he was from the Chinese autonomous region of Xinjiang, home to the Uighurs.

Izan also used a Chinese passport, Thai police said.