The authorities in Thailand are preparing to charge a 14-year-old boy with first-degree murder today after he launched a gun attack at an upscale Bangkok mall yesterday using what police say was a modified handgun that was originally designed to fire blanks.

The suspect suffered a mental breakdown after the attack he launched inside the Siam Paragon, killing two women — one from China and one from Myanmar — and injuring five other people.

This was the third armed attack to rock Thailand in the past three years.

The 14-year-old surrendered when police cornered him inside a designer furniture store.

Police have announced they will seek to charge him with premeditated murder, attempted murder, possession of an illegal weapon and using it in a public place.

“We still can’t get a statement from him because the doctor said he has a psychiatric problem,” Bangkok police Lt. Gen. Nakarin Sukondawit told Reuters.

Mass killings are rare in Thailand, but gun violence and gun ownership are commonplace. Gun laws are strict, but guns can be modified and bought illegally, many smuggled in from abroad.

Police said the teenager had converted a gun designed to shoot blanks, which is widely sold.

One of the most photographed places on Instagram, Siam Paragon is Thailand’s most famous shopping mall attracting daily crowds of local and foreign visitors who shop in its luxury shops or visit its aquarium, cinemas and restaurants and cafes .

Today flowers were placed at its entrance when it reopened its doors, while workers replaced the broken glass of a Louis Vuitton store.

Prime Minister Sretha Thavisin attended a technology event held at the mall and told reporters that access to guns — including those that can be modified — is something his government will address in cooperation with the police.

“They can buy them online, so we need to put more restrictions on people’s access to these dangerous things,” he said.

The Chinese embassy in Bangkok announced that the Thai prime minister had a telephone conversation with its ambassador and pledged to “strengthen public security to provide a reliable and safe environment for Chinese citizens traveling to Thailand.”

Thai police chief Torsak Sukwwimol said the suspect was receiving psychiatric treatment and had not taken his prescribed medication when he launched the attack.

Investigators are looking into his background and plan to talk to his friends, including his online gaming teammates, about his mental state.

“We will have to investigate whether the suspect had a history of aggressive and violent behavior,” said Torsak, who met with the boy shortly after the attack.

“At first I talked to him to reassure him … he seemed to be hearing someone talking to him, hearing things, a voice telling him to shoot, as he said,” Torsak told the media.