A gunman killed five people at a market in Thailand's capital Bangkok on Monday, attacking security guards and a merchant before fatally turning the gun on himself, a Thai police official said. The gunman initially killed three security guards, and then a fourth with whom he had a personal quarrel, Siam Bunsom, commander-in-chief of the Metropolitan Police Bureau said. "He reloaded and ran into the market, killing a female merchant and injuring another," Siam told reporters. In video footage shared by police, a suspect in a white hat and a backpack slung on his chest is seen walking through a parking lot at the Or Tor Kor Market. Duangnapa Yeerunsiri, 38, who was at the market to buy groceries with her boyfriend and sister, was about to leave when she heard the shots ringing out. "He fired many shots in rapid succession," she said, referring to the gunman. "So we ducked down in the car and quickly called the police." No tourists were killed or injured, said Sanong Saengmani, a police official in Bangkok's Bang Sue district, where the market, which mainly sells agricultural produce, is located.