A 14-year-old with a gun opened fire at a luxury shopping mall in downtown Bangkok on Tuesday, authorities said, killing three people and injuring four in one of Thailand’s most popular tourist destinations.

The shooting started around 4.20pm (local time) in the Siam Paragon mall, according to Bangkok police. The suspect was arrested within the hour, according to the force’s metropolitan bureau. The Erawan Centre, a Bangkok emergency response centre, provided the casualty count.

On social media, witnesses uploaded videos of people screaming as gunshots were heard in the bathroom of a mall. Other video clips showed the injured being taken away in an ambulance.

Mass shootings are rare in Thailand, where gun regulations are relatively strict. It remains unclear how a 14-year-old would have come to possess a firearm. Would-be buyers must be older than 20, undergo a background check and provide a reason for ownership.

Prime Minister Srettha Thavisin wrote on X, formerly known as Twitter, that he had “instructed the police commissioner to go investigate and monitor the situation”, adding: “What I worry about the most is the safety of all the people.”

The motive for the shooting was unknown. The suspect had just turned 14 in September.

A video of the suspect in police custody showed a bespectacled teenager dressed in a cap with an American flag, wearing a black polo T-shirt and shorts with blood spatter on them.

Siam Paragon, situated in the heart of downtown Bangkok and opposite the headquarters of the Royal Thai Police, is a luxury mall popular among tourists and locals. The shooting prompted authorities to seal off the subway station linked to the mall.

The attack occurred almost exactly a year after a former police officer armed with a handgun and a knife went on a rampage in a daycare center in northeastern Thailand, killing 36 people, 24 of them children. It was the worst mass shooting by a sole perpetrator in Thailand’s history, prompting a debate about whether gun laws should be tightened in the country.

Police spokesman Archayon Kraithong told reporters the situation was under control at the mall, which sells high-end fashions and luxury cars, and includes a cinema, an aquarium and the five-star Siam Kempinski Hotel.