Thai police on Saturday said an arrest warrant had been issued for a "Chinese" man over last month's deadly Bangkok blast, backtracking after they earlier identified the suspect as a member of the country's Uighur minority.

National police spokesman Prawut Thavornsiri told AFP the suspect was a Uighur according to his passport, as authorities released a photo of the moustached and short-haired suspect, with a caption that identified him as Abudusataer Abudureheman, or "Ishan", of "Uighur" ethnicity and "Chinese" nationality.

But shortly afterwards police sent reporters another photo of the suspect -- this time removing mention of his ethnicity and requesting media "drop the word Uighur".

Later Saturday, Prawut said he wanted to "correct" his earlier comment, without explaining why or denying whether the man was of Uighur ethnicity, saying only the suspect was Chinese.

"I cannot confirm his whereabouts," the spokesman added.

Confusing and sometimes contradictory official statements have characterised updates into the investigation of the attack which killed 20 people, the majority ethnic Chinese visitors, at a religious shrine in the capital's bustling downtown district on August 17.

Analysts have increasingly pointed towards militants from China's mostly Muslim Uighur minority -- or their supporters -- in revenge for Thailand's forced deportation of 109 Uighur refugees to an uncertain future in China in July.

Up until Saturday, Thai police had avoided attempts to directly connect the blast with the kingdom's major ally China or the Uighurs.

- Diplomatic awkwardness -

Thai authorities are already holding in custody two foreign men, whose nationalities remain unconfirmed, over the attack. Ishan, who police say is 27 years old, is among another 11 suspects wanted by police.

Prawut said Ishan, who left Thailand a day before the blast and is wanted on the charge of "jointly possessing illegal military supplies", belonged to the criminal network that police believe is responsible -- but he was "not the mastermind" of the attack.

That appeared to be yet another contradiction to a statement, also released Saturday, by Thai immigration police that said: "According to security agencies, Ishan is the one who plotted, ordered, and funded the attack."

That statement also referred to Ishan being of Uighur ethnicity.

It was not immediately clear why the police retracted the Uighur claim, but Thailand's junta has been keen to avoid awkward diplomatic questions -- in particular from China, whom is has relied on more strongly as an ally since last year's coup.

Uighurs have long accused Beijing of religious and cultural repression, with scores believed to have fled China's northwestern Xinjiang region -- home to around 10 million of the group -- in recent years, often heading to Turkey via Southeast Asia.

Thailand's recent deportation of Uighurs had sparked violent protests in Turkey, where nationalist hardliners see the minority as part of a global Turkic-speaking family.

The warrant issued Saturday is the 12th over the unprecedented attack on the Thai capital, which targeted a Hindu shrine particularly popular with Chinese tourists who believe prayers there bring good fortune.

Mystery still surrounds the motives of the group accused of being behind the attack, and Thai authorities have been careful not to suggest that Chinese visitors were targeted.

One of the detained suspects, Yusufu Mieraili, was arrested last month with a Chinese passport registering his birthplace as Xinjiang.

But police did not confirm his ethnicity or nationality nor that of the other detained suspect, Adem Karadag, who was arrested at a Bangkok flat in possession of bomb-making materials and scores of fake Turkish passports.

Mieraili has confessed to handing over a backpack containing the four-kilogramme bomb to another, unnamed, man who was later caught on CCTV wearing a yellow T-shirt and placing the bag at the busy shrine moments before the blast.

On Thursday, Bangladesh police confirmed a suspect from the bombing network had arrived in Dhaka from Bangkok on August 16 before flying out to Beijing two weeks later.

But local Thai media reports have said the suspect flew on to Turkey rather than China.