Rangsirit Pimpa, a Mathayom 2 student of Wat Kemapirataram School, was slashed and stabbed in the neck by three teenagers in Soi Rambutri near Khao San Road. The attack happened about 8pm during Songkran festival activities. He later died from his injuries.
The suspects, aged 15 and 17, were captured on Saturday morning, said Pol Lt Col Somyos Udomraksasap, deputy chief of Chana Songkhram Police Station.
The names of the suspects have not been disclosed because they are minors. The warrants for their arrest were issued by the Central Juvenile and Family Court on Friday, Pol Lt Col Somyos said.
The suspects will face charges of murder, carrying weapons in public places without an appropriate reason and violation of orders under the Internal Security Act, he said.
According to Pol Lt Col Somyos, police had been unable to obtain an arrest warrant for a third suspect because witnesses could not confirm he was involved.
He said the investigation found that Rangsirit was celebrating the Songkran festival with a large number of friends before being attacked.
The teens arrested deny their involvement in the killing, but Pol Lt Col Somyos said police had clear evidence to substantiate the charges against them.
The suspects are school students, and he speculated that motives could include personal conflicts or inter-school rivalry. They were still being questioned yesterday.
Details about the murder have been widely circulated on social media to draw attention to the case. Some information posted online suggested one of the attackers wore a school uniform during the assault.
Online posts also suggested that CCTV cameras in the vicinity of the attack scene were faulty.
Some posts accused officials and the media of turning a blind eye to the case.
This prompted Pol Lt Col Somyos to deny accusations that police were not concerned about the case.