Thai police are pressing ahead with their manhunt for those responsible for the deadly Erawan shrine blast, even as they confirmed yesterday that the suspect in a yellow T-shirt seen on closed-circuit television footage is in their custody.

Much of the investigation has been focused on the man seen leaving a backpack at the shrine just before the rush-hour blast on Aug 17.

The explosion left 21 people dead, 14 of whom were foreigners, including one Singaporean.

The hunt for the bomber has been marked by uncertainty and contradictory statements over two foreign men detained as suspects.

Thai police had earlier denied that either of them was the bomber. But yesterday, national police spokesman Prawut Thavornsiri told reporters that Adem Karadag, the first of the two detained, was the Erawan shrine bomber.

"It is confirmed that Adem is the man in the yellow shirt based on CCTV footage, eyewitness accounts and his own confession," Lieutenant-General Prawut said.

"After he placed the bomb at the shrine, he hailed a motorcycle taxi and changed his shirt at a toilet in Lumpini Park."

The park in central Bangkok is minutes away from the shrine.

The round-up of people connected to the bombing is by no means over. A military court on Friday issued arrest warrants for 17 people, including Karadag, as well as others carrying Thai, Chinese and Pakistani passports.

According to Lt-Gen Prawut, these included people who had bought bomb-making materials and SIM cards, or rented rooms used by the bombers.

Karadag, whose nationality remains unclear, faces up to eight charges, including premeditated murder.

He will be tried in a military court, Lt-Gen Prawut told The Sunday Times.

Military tribunals have jurisdiction over lese majeste cases as well as crimes against national security in Thailand, which has been ruled by a military government since last year's coup.

Karadag and Yusufu Mieraili, another foreigner arrested over the bombing, were questioned in military facilities.

Karadag was arrested last month in the outskirts of Bangkok, reportedly with fake Turkish passports and material used to assemble a bomb.

His lawyer Choochart Khanphai, who says Karadag's real name is Bilal Mohammed, had previously said he was born in China's Xinjiang region, but moved to Turkey in 2004 where he became a citizen.

He also claimed that his client had entered Thailand four days after the bombing.

In an elaborate re-enactment yesterday - a standard procedure by the Thai police - armed soldiers and policemen surrounded the shrine while a sullen and handcuffed Karadag, who was in a yellow T-shirt, was escorted there carrying a backpack and a plastic bag.

Mieraili, who allegedly supplied the bomb, also took part in the public re-enactment.

He has a Chinese passport, which places Xinjiang as his birthplace.

Xinjiang is home to China's minority Uighur Muslims, who say they are oppressed by the Chinese authorities. For weeks after the bombing, speculation was rife that the bombing was carried out in retaliation for Thailand's deportation of over 100 Uighurs in July.

But Thai police have dismissed the theory, claiming instead that it was conducted by a human smuggling network upset over a police crackdown.

The Thai authorities - wary that the attack would put off tourists - have insisted that the blast has nothing to do with terrorism.

No group has claimed responsibility for the attack or made the motive clear.