Story by the Associated Press; curated by Dave Urbanski

BANGKOK (AP) — A gunman has opened fire on anti-government protesters in Bangkok, seriously wounding one man.

The shooting overnight Saturday was the latest in a series of mysterious attacks on demonstrators trying to oust Thai Prime Minister Yingluck Shinawatra.

Gun Attack on Thailand Anti Government Protesters Wounds One

Thai anti-government protesters hold a candle vigil for the protester killed during yesterday’s bomb blast on the sixth day of the ‘Bangkok Shutdown’ on January 18, 2014 in Bangkok, Thailand. An explosive device went off during an anti-government protest march, wounding dozens and killing one. Explosions and gunshot incidents have been happening as the protesters have stepped up their activity with daily marches in the on-going attempt to oust the government of Thai PM Yingluck Shinawatra. (Image source: Getty Images/Paula Bronstein)

Gun Attack on Thailand Anti Government Protesters Wounds One

Thai anti-government protesters hold a candle vigil on January 18, 2014 in Bangkok, Thailand. (Image source: Getty Images/Paula Bronstein)

It is not clear who is behind the violence.

Bangkok’s emergency medical center said the man was shot in the back in the city’s Lad Prao district. He underwent surgery at a hospital and was in an intensive care unit.

Thai media identified the man as a 54-year-old from southern Thailand who was helping to guard protesters.