Some Singaporeans were among those injured, the Singapore Embassy in Bangkok told The Straits Times Online.
The force of the blast was so great that an iron fence surrounding the shrine was bent outward.
In the first explosion, an improvised explosive device fastened to a utility pole in front of the Erawan Shrine at the Ratchaprasong intersection detonated at 6.55pm (7.55pm Singapore time), reported the Bangkok Post.
The Hindu shrine is a popular tourist attraction, which sees a regular stream of Singapore visitors. A second bomb on a motorcycle went off later, causing two nearby taxis to explode.
Charred and shattered motorcycles littered the scene, along with hunks of concrete from the shrine, with pools of blood on the pavement and bodies, which were later covered with white sheets, reported AFP.
Mr Marko Cunningham, a New Zealand paramedic working with a Bangkok ambulance service, told UK's The Mirror that the blast left a two-metre-wide crater.
He said that there were bodies everywhere: "Some were shredded. It was like a meat market. There were legs where heads were supposed to be. It was horrific."
Eyewitness Richard Sri-kureja told BBC Online that he was walking to a mall next to the shrine when the bomb went off.
He said: "There was total chaos. They blocked off the area, everyone was running in totally different directions."
He saw that a local hotel was packed with injured victims.
"Everyone was trying to help as much as they could. Other people were taking photos," he said.
The explosions killed at least 16 people, including at least one from China and one from the Philippines.
It also left more than 80 others injured. Most of those injured in the explosion were said to be Asian tourists from China and Taiwan. At press time, there were no details on the injured Singaporeans.
The majority were taken to the Police General Hospital, reported the Bangkok Post.
The military and police also found two more explosive devices at the scene and military explosive ordinance disposal technicians defused both without incident, reported the Bangkok Post.
There was no immediate claim of responsibility, Reuters reported.
"It was a TNT bomb... the people who did it targeted foreigners and to damage tourism and the economy," Thailand's Defence Minister Prawit Wongsuwong told AFP.
The government would set up a "war room" to coordinate its response to the blast, the Nation television channel quoted Prime Minister Prayuth Chan-ocha as saying.
Some Singaporeans have been injured in the explosion. Our Bangkok Mission staff have met them, and are rendering consular assistance.
- Prime Minister Lee Hsien Loong in a Facebook post.
Popular spot with S’poreans
A photo of the aftermath of the blast at Erawan Shrine that a friend sent via WhatsApp made me shudder.
It was a half-blown body in front of a table that I am so familiar with. The very spot where the body lay is where I would stand inside the Shrine once a year, to make payment for a thanksgiving performance by Thai dancers.
Next to the table is a spot where I would kneel, as the troupe of performers sing in Thai, calling out the names of my family members, and dance as I offer prayers to the Four-Faced Buddha.
It is not just a tourist spot for me. There are times when I visit more than once a year. That is how significant the shrine is to me, and hundreds of Singaporeans.
I dare say, it is probably the one place you would find more Singaporeans at any one time than others.
There have been many occasions when I have bumped into familiar faces - friends, and even local celebrities there.
The shrine is on a busy corner near top hotels, shopping centres and offices. Many ordinary Thais also worship there.
As the news began to filter out, friends started sharing messages of disbelief. Shocked, worried and upset.
Ms Candy Soh, 34, a real estate agent, said: "The first thought that crossed my mind was - was the shrine damaged? And were there any casualties?"
She offers prayers there twice a year.
"Erawan Shrine shows me the light when I'm down, and gives me hope when I'm asking for directions," she said.
Singaporean Gilaxs Goh, 51, who runs a travel agency here and another in Bangkok, said: "The first call I got was from a Thai police officer contact (of mine) who was worried that I was in Bangkok."
Five Singaporeans, who had booked a trip through his agency, had just arrived in Bangkok.
"I contacted them and advised that they remain in the hotel area for now," said the owner of Value Tour, who is in Singapore.
He added: "Things had started to settle down in the past year and now this. Of course I am very upset."
The shrine, he said, is one of the must-go to places for Singaporeans. Mr Goh hopes the blast will not deter Singaporeans from travelling to the Thai capital.
"I pray that peace will return soon," he said.
This article was first published on August 18, 2015.
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