The death toll in a powerful bomb blast outside the popular Hindu Erawan shrine in the heart of the Thai Capital rose to 21 on Tuesday with more than 120 injured, even as the country's defence minister said investigators were closer to determining who set off the device.
"It is much clearer who the bombers are, but I can't reveal right now. We have suspects. There are not many people," defence minister Prawit Wongsuwan said.
Thailand's junta chief Prayut Chan-O-Cha described the bombing as the "worst ever attack" on the country.
Twelve people died at the scene of the blast in central Bangkok on Monday evening and ten more died in nearby hospitals, police spokesperson Lt Gen Prawut Thavornsiri told the media. He said 123 people were wounded.
Seven tourists from China, Hong Kong, Malaysia and Singapore were among the dead. The Indian envoy had said on Monday that no Indians were among the casualties.
"It was like this huge gust of wind and debris flying through you," Sanjeev Vyas, a DJ from Mumbai who was in the middle of the fray, told CNN. "... And then I see bodies everywhere, there are cars on fire, there are bikes everywhere. People are screaming."
Earlier, authorities had ordered onlookers back, saying they were checking for a second bomb but police later said no other explosive devices were found.
Yet security checks at some major city intersections and in tourist areas had been stepped up. The city's elevated railway, which passes over the scene, was operating normally.
Bangkok has endured years of deadly political violence, with a military junta now ruling the nation, and a decades-long Muslim insurgency in the far south that has claimed thousands of lives.
Government spokesperson Werachon Sukhondhapatipak told reporters, "It's too early to link the bomb to terrorist attack because no group has come to claim responsibility so far."
However, officials said the attack targeted Thailand's tourism industry although it is unclear who stands to gain.
CCTV footage:Moment massive bomb explosion rocked Bangkok
Islamic militants have carried out many attacks in other parts of southeast Asia, including on Indonesia's holiday island of Bali in 2002 that killed 202 people, but so far, Thailand had not been a target. Sukhondhapatipak further said that the pipe bomb detonated was not similar to those used by insurgents in the south.
United Nations general secretary Ban-Ki-moon condemned the attack and expressed "his condolences to the bereaved families and to the people and government of Thailand". "He hopes that those responsible will be brought to justice," the statement read.
Prime Minister Narendra Modi also tweeted about the explosion that took place outside a Hindu temple in the Thai Capital. "I strongly condemn the blast in Bangkok. My thoughts are with the families of the deceased. I pray for a speedy recovery of the injured," the tweet read.
The army has ruled Thailand since May 2014, when it ousted an elected government after months of at times violent anti-government protests.
The shrine intersection was the site of months of anti-government protests in 2010 by supporters of ousted former Prime Minister Thaksin Shinawatra. Dozens were killed in a military crackdown and a shopping centre was set ablaze.