Twenty-eight people were taken to several hospitals across the city, according to the Erawan Emergency Center. Protesters said the injuries were caused by two separate blasts at a rally.
The Erawan Medical Center says the injured were taken to four different Bangkok hospitals.
It was not immediately clear what caused the explosion Sunday afternoon.
Late Saturday night, a gunman opened fire on anti-government protesters elsewhere in the capital, severely wounding one man.
And on Friday, an explosive device hurled at a crowd of marching demonstrators killed one and wounded dozens.
It is unclear who is behind the unrest. With a report from Associated Press
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