The teenager has been charged with murder over Tuesday’s attack at the Siam Paragon mall, which police say was carried out with a blank-firing pistol modified to shoot live rounds.
Two of the four were arrested in Bangkok and two in the southern province of Yala on suspicion of selling a gun to the boy.
“There was also live streaming equipment,” police official Samran Nuanma told reporters outside the home of one suspect, adding that he suspected that sales took place on social media.
The men also had illegal firearms, tools to modify pistols and narcotics in their possession, he added.
Thai mall shooting: PM reassures tourists about safety amid gun law debate
Thai mall shooting: PM reassures tourists about safety amid gun law debate
Hundreds of shoppers fled the packed upmarket mall in fear as shots rang out on Tuesday afternoon.
Seven people were shot in total, and a woman from China and another from Myanmar were killed.
The 14-year-old suspect has been charged with attempted murder, carrying and firing a gun in a public place, and owning an unlicensed firearm.
He is undergoing psychiatric testing to see if he is fit to stand trial – he had previously been receiving treatment for a mental illness but had stopped taking medication, according to police.
The shooting has sparked fresh calls for tighter gun control in a country awash with both legal and illegal weapons.
The government also began closing legal loopholes regarding online sales in a bid to control the spread of weapons.
“The digital ministry will be shutting down websites selling blank guns,” Jakkapong Sangmanee, the deputy foreign minister, told a separate briefing.
The government plans to ban imports of blank guns, BB guns and imitation firearms, its deputy spokesperson, Karom Phonphonklang, said in a statement.
It will also stop issuing additional permits for gun imports and permits for possession.
‘May God bless their souls’: Johor crown prince recounts Thai mall shooting
‘May God bless their souls’: Johor crown prince recounts Thai mall shooting
According to an international database, Thailand has an estimated 10 million guns in circulation – one for every seven citizens, and one of the highest rates of ownership in the region.
In 2020, a soldier gunned down 29 people in a mall rampage at Nakhon Ratchasima.
Thai Prime Minister Srettha Thavisin on Wednesday vowed to bring in “preventive measures” to prevent further tragedies.
Additional reporting by Reuters
