Goa, Aug. 7 -- Thailand Prime Minister Anutin Charnvirakul has said the 14-year-old suspected of carrying out a deadly shooting at a school near Bangkok was under stress related to his schooling and appeared to have planned the attack.

The teenager allegedly killed seven people, including his grandparents, before taking his own life. Speaking outside Debsirin Nonthaburi School in Nonthaburi province, Anutin said police had spoken to the suspect's close friend, who indicated that the teenager had been experiencing school-related stress.

The Prime Minister said the suspect's actions also suggested that the shooting had been planned. Police said the teenager fired at least 26 rounds using his grandfather's gun, while another 34 rounds were...