Bangkok: Thai police said on Wednesday they had still not established the nationality or whereabouts of the man they suspect bombed a popular Bangkok shrine, killing at least 20 people, suggesting the trail had gone cold after he was captured on CCTV at the scene.
Authorities said they were keeping watch for the suspect at the country`s borders, but police chief Somyot Pumpanmuang told a news conference it was not clear how many people were involved in the attack or if they were still in Thailand.
"I don`t suspect one person, I suspect many people," he said. "I am confident there are Thais involved, but I am not saying it is just Thais or that there are foreigners."
On Tuesday, a day after the bombing at the Erawan shrine in the heart of Bangkok, grainy closed-circuit television (CCTV) footage was released showing a young man dumping a backpack at the scene and walking away.
The government says the attack was aimed at wrecking the economy, which depends heavily on tourism.
No one has claimed responsibility for the blast, which according to the latest official toll killed 20 people - more than half of them foreigners from several Asian countries - and wounded more than 120.
Deputy police chief Jaktip Chaijinda said earlier that investigators believed the man on the video resembled a foreigner more than a Thai. A sketch of the suspect released on Wednesday showed a fair-skinned man with thick, medium-length black hair, a wispy beard and black glasses.
At least two foreigners have been interviewed in connection with the blast, police said.
Jangling nerves in the city on Tuesday, a small explosive was thrown from a bridge towards a river pier, sending a plume of water into the air, but no one was hurt. A government spokesman initially said there were "patterns" linking the two bombs which both used TNT, but police chief Somyot said no direct connection between them had been established.
Police Major General Pornchai Suteerakune, commander of the Institute of Forensic Medicine, said the bodies of almost all those killed at the shrine had wounds inflicted by ball bearings that were packed into the bomb.
The shrine, a blood-spattered scene of charred motorbikes and debris after the blast, was reopened on Wednesday.
NO CLEAR TELL-TALE SIGNS
The CCTV footage of the youth with a yellow T-shirt shows him entering the shrine compound with a backpack on, sitting down against a railing and slipping out of the bag`s straps.
He then stands up and walks out apparently holding a mobile phone, leaving the bag by the fence as tourists mill about.
"From looking at the CCTV footage we think that the yellow shirt man was maybe operating with one or two other people at the scene," police spokesman Prawut Thavomsiri said, without elaborating.
Prawut earlier tweeted that police were offering a 1 million baht ($28,100) reward for information leading to the arrest of the suspect.
Police have not ruled out any group for the attack, including elements opposed to the military government, though they say it did not match the tactics of Muslim insurgents in the south or so-called `red shirt` supporters of the previous administration.
"The attack did not bear the hallmarks of either southern Muslim separatists or red-shirt militants," said Angel Rabasa, an expert on Islamist militancy at the RAND Corporation.
He said the attack could be the work of Islamic State, which has been expanding its reach in Southeast Asia, or an al Qaeda related or independent jihadist group. However, such groups usually claim responsibility for their attacks.
Police said they were also considering the possibility that ethnic Uighurs were behind the bombing. Thailand forcibly returned 109 Uighurs to China last month.
Hundreds, possibly thousands, of members of the Turkic-speaking and largely Muslim minority have fled unrest in China`s western Xinjiang region, where hundreds of people have been killed, prompting a crackdown by Chinese authorities. Many Uighurs have travelled through Southeast Asia to Turkey.
However, Prime Minister Prayuth Chan-ocha sought to cool speculation of a revenge attack by Uighurs. "I have always said that what the government did was within the boundaries of the law and by international agreement," he told reporters. "If we did not send them they would have been a burden to Thailand. I don`t want this issue raised."
The blast comes at a sensitive time for Thailand, which has been riven for a decade by a sometimes-violent struggle for power between political factions in Bangkok.
A parliament hand-picked by a junta that seized power in a 2014 coup is due to vote on a draft constitution next month. Critics say the draft is undemocratic and intended to help the army secure power and curb the influence of elected politicians.