Thai police have issued an arrest warrant for the chief suspect in Monday's deadly bombing in Bangkok and offered a 1 million baht (S$39,500) reward for information, amid jitters about follow-up attacks.
They are also looking for two other men seen near the scene of the blast site.
According to police, the chief suspect was overheard speaking a foreign language other than English.
"Foreign language... not English also," national police spokesman Prawut Thavornsiri said when asked by reporters whether a man seen leaving a backpack in the shrine minutes before Monday's deadly explosion spoke any foreign languages.
Prawut did not elaborate on how police knew the suspect spoke a foreign language.
But police said earlier they had interviewed two motorcycle taxi riders near the shrine, one of whom gave a ride to the suspect.
Prawut also gave a description of the suspected ethnicity of the alleged bomber, using the Thai phrase "khaek khao" - a word often used to describe light-skinned Muslims from South Asia, Central Asia and the Middle East.
"His skin is white and he has a high nose. Whether khaek khao or not I don't know. But from the footage it looked like that," he said, speaking during a walkabout in Soi Cowboy, one of the city's famous red light districts, as part of a police push to reassure tourists after the deadly blasts which have left the city reeling.
Earlier on Wednesday, a Bangkok court issued an arrest warrant for the unnamed man, who was filmed on security footage dropping off the backpack that is believed to have contained the bomb.
The warrant described him as a tall foreigner with white skin.
Police said on Wednesday that two other men seen in CCTV footage are also suspects.
"The person in red and the person in white are also suspects," police spokesman Prawut said in a televised interview, referring to two men seen in grainy closed-circuit television footage along with a man in a yellow t-shirt who police believe is linked to the attack.
The government rushed to reassure visitors that the country was still a safe destination as Erawan Shrine - the site of horrific carnage three days ago - re-opened to the public.
A constant stream of people turned up yesterday to offer flowers and notes in memory of the victims.
Twenty people died, including a Singaporean woman, and more than 120 others were injured, in an attack which analysts described as unprecedented in scale and method even in the context of the country's turbulent political history.
No one has claimed responsibility so far.
National police chief Somyot Poompanmoung told reporters the attack was likely the work of a group rather than an individual.
"He didn't do it alone," he said.
A section of Sukhumvit Road running through the capital was closed off briefly yesterday afternoon after the discovery of a suspicious object. It turned out to be a false alarm.
The scare came one day after a bomb was hurled off a bridge by the Chao Phraya River in the city, detonating harmlessly underwater. City officials and police were working to collect bomb fragments for further examination.
Prime Minister Prayut Chan-o- cha asked the culprit to turn himself in for his own safety.
"I am worried the person who planted the bomb will be killed," local reports quoted him as saying. "I would like to advise him to surrender himself if he wants to be safe."
The blast on Monday took place at about 7pm, during the rush hour in an area that is packed with tourists making offerings at the shrine.
Yesterday, Thai government officials visited victims of the blast in hospital to process the paperwork for compensation. In daily television announcements made in Thai, English and Mandarin, the ruling junta has assured the victims and relatives of the deceased that it would take care of their medical expenses and make monetary compensation.
"The situation is back in order. People are able to move on with their lives normally," Colonel Winthai Suvaree, a spokesman for the National Council for Peace and Order, said on television yesterday.
Thai stocks also rebounded after taking a hit immediately after the blast, though the baht continued its slide to a fresh six-year low. There are fears that the attack's impact on tourism, which accounts for some 10 per cent of Thailand's gross domestic product, may be more extensive than thought.
Singaporean Ng Su Teck, whose wife, insurance company executive Melisa Liu Chun Rui, 34, died in the blast, told The Straits Times that he hoped to return to Singapore together with her body.
Mr Ng, 35, was hospitalised himself after being injured by shrapnel in the explosion. The Straits Times understands that he was discharged yesterday and due to return to Singapore last night.
Social and Family Development Minister Tan Chuan-Jin yesterday urged people to remain vigilant.
"There are terrorist acts across the world every day. We register it intellectually and sometimes emotionally. But nothing quite brings it home until you lose one of your own," he wrote in a Facebook post.
"Stay alert. But we cannot be cowed. Life must and will go on."