At least 21 people, including many foreign tourists, were killed on Monday evening when a powerful bomb planted on a motorcycle exploded outside a hugely popular Lord Brahma temple in the Thai capital, scattering body parts and debris.
There were no reports of any Indian casualties.
The explosion outside the Erawan shrine in the crowded business district of Chidlom also injured at least 100 people, most of them tourists from China and Taiwan, local media quoted rescue agencies as saying. Some reports of 27 casualties were denied by officials.
"The perpetrators intended to destroy the economy and tourism, because the incident occurred in the heart of the tourism district," defence minister Prawit Wongsuwan told Reuters.
“It was like a meat market,” said Marko Cunningham, a paramedic, adding the blast had left a two-metre-wide crater. “There were bodies everywhere. Some were shredded. There were legs where heads were supposed to be. It was horrific.”
The shrine is a major attraction, especially for visitors from China. Thousands of Buddhist devotees also visit it every day.
The government would set up a "war room" to coordinate the response to the blast, the Nation television channel quoted Prime Minister Prayuth Chan-ocha as saying.
CCTV footage: Moment massive bomb explosion rocked Bangkok
A tweet by Bob James, a sub-editor with Bangkok Post Digital Media, said the police believed most of the people injured were foreign tourists.
The external affairs ministry has tweeted the emergency numbers and the contact number of the Indian embassy for any Indian in distress.
Bangkok blast: Any Indian in distress should contact Indian Embassy. Emergency no +66618819218. Embassy landline numbers: +6622580300-5— Vikas Swarup (@MEAIndia) August 17, 2015
Indian Prime Minister Narendra Modi has condemned the bomb blast that took place outside a Hindu temple in 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," he tweeted.
Medical workers rush the victim of a blast at the Erawan shrine to a nearby hospital in central Bangkok August 17, 2015. The bomb planted at one of the Thai capital's most renowned shrines on Monday, killed over a dozen people and wounded scores . (REUTERS)
At the scene lay burnt out motorcycles, with rubble from the shrine's wall and pools of blood on the street.
Earlier, authorities had ordered onlookers back, saying they were checking for a second bomb but police later said no other explosive devices were found.
Authorities stepped up security checks at some major city intersections and in tourist areas. The city's elevated railway, which passes over the scene, was operating normally.
While initial suspicion might fall on Muslim separatists in the south, Thailand has been riven for a decade by an intense and sometimes violent struggle for power between political factions in Bangkok.
Occasional small blasts have been blamed on one side or the other. Two pipe bombs exploded outside a luxury shopping mall in the same area in February, but caused little damage.
Police said that attack was aimed at raising tension when the city was under martial law.
The army has ruled Thailand since May 2014, when it ousted an elected government after months of at times violent anti-government protests.
A Thai junta military chief stated on Tuesday that police were searching for a male suspect seen on CCTV near the bomb-site.
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.