Explosions and gunshots injured almost 30 people at a rally in central Bangkok on Sunday, part of a continuing "shutdown" protest aimed at toppling the Thai government, an emergency centre said.
Twenty-eight people were taken to several city hospitals, according to the Erawan Emergency Centre. It was not immediately clear how serious the injuries were.
"There were two explosions and gunshots at Victory Monument," the centre said in a statement on its website, referring to a major intersection held by the protesters since Monday.
"Intially 28 were injured, we are chasing more details."
Reports said the blasts were followed by a shootout with the apparent attackers.
It was the latest in a series of attacks by unknown assailants on demonstrators seeking to oust the government of Prime Minister Yingluck Shinawatra.
Protesters said the injuries were caused by two separate blasts minutes apart at a rally.
"People were speaking on stage when there was a loud explosion," said Theerayuth Utakaintanond, 52.
"Almost two minutes later, I think, I heard another explosion and everyone started to run in panic."
There were blood-splattered clothes and a small crater at the scene of one of the blasts, according to an AFP reporter.
On Friday one protester died and dozens were injured in a blast at an anti-government protest march in the city.
