The Nation television said 27 had been killed in the blast at the Erawan Hindu shrine, and other media said at least three foreigners were among them. Most of the injured were tourists from China and Taiwan, media said.
At least two bombs were found at the scene, said Maj. Gen. Weerachon Sukhondhapatipak, a spokesman for Thailand's ruling junta. He said at least one had detonated.
The explosion took place at the Rajprasong intersection, which was the center of many contentious political demonstrations in recent years. It occurred in front of the Erawan Shrine, a tourist landmark also popular with Thais.
The first bomb was found inside the shrine compound, while the second was found opposite the complex, Weerachon said.
A Reuters witness at the scene said she saw pieces of human flesh near the blast site, and a soldier later told onlookers to move back, saying they were checking for a second bomb.
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.
NDTV, quoting India's envoy, said there were no reports of Indians being hurt in the explosion.
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.
Thai forces are fighting a low-level Muslim insurgency in the predominantly Buddhist country's south, although those rebels have rarely launched attacks outside their ethnic Malay heartland. The country has also been riven for a decade by intense and sometimes violent rivalry between political factions in Bangkok and elsewhere.
The army has ruled Thailand since May 2014, when it ousted an elected government after months of, at times, violent anti-government protests.
The Erawan shrine, on a busy corner near top hotels, shopping centres and offices, is a major tourist attraction, especially for visitors from East Asia. Many ordinary Thais also worship there.
Motorcycles lie on the street at the scene of the explosion near the
Erawan Shrine in central Bangkok. Photograph: Ritchie B Tongo/EPA
A bomb has exploded outside a Hindu shrine
in central Bangkok, killing at least 12 people and wounding many more,
according to a police officer and rescue worker at the scene.
Body parts and mangled scooters were
scattered across the street after the explosion outside the Erawan shrine in
the central Chidlom district of the Thai capital.
Dozens of ambulances are at the scene and a
nearby metro station has been closed. There are unconfirmed reports in Thai
media that the death toll is at least 27, including four foreigners.
A spokesman for Thailand’s ruling junta
said a second bomb at the scene had been found and made safe.
A police chief told Reuters: “All I can say
now is there has been an explosion in central Bangkok involving a motorcycle
bomb.” He said there had been fatalities, but could not confirm details.
Police and a rescue worker told Reuters 12
people had been killed in the blast, which happened at about 7pm local time
(12.00 GMT). Local media put the number of injured at 20.
Thanapon Peng, 25, passed the site on a
motorbike taxi moments after the blast.
“I saw glass. I saw some organs of people
on the road. I don’t know how many people there were,” he told the Guardian in
the lobby of the Grand Hyatt hotel, where tourists and Thais have been waiting
until they get the all clear to leave.
“I heard that about 80 people are wounded
but we don’t know how many died.”
Police with torches have been looking under
bushes and walking the grounds of the nearby Royal Thai police station in an
apparent effort to search for other bombs.
A long line of ambulances has formed
outside a hospital located close to the blast site, so many of the injured are
being taken to medical centres further away.
There was no immediate claim of
responsibility. Thai forces are fighting a low-level Muslim insurgency in the
predominantly Buddhist country’s south, although those rebels have rarely
launched attacks outside their ethnic Malay heartland.
The country has also been riven for a
decade by intense and sometimes violent rivalry between political factions in
Bangkok and elsewhere.
The army has ruled Thailand since May 2014,
when it ousted an elected government after months of, at times, violent
The Erawan shrine, on a busy corner near
top hotels, shopping centres and offices, is a major tourist attraction,
especially for visitors from East Asia. Many Thai people worship there.
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.
France-Presse and Reuters contributed to this report