Students and school staff who fled the shooting were distraught as they waited outside the school At least seven people have been killed and more than 30 injured after a 14-year-old boy opened fire at his home and school on the outskirts of Thailand's capital Bangkok. The student killed his grandparents and five teachers before taking his own life, Thai Prime Minister Anutin Charnvirakul told reporters. The attacker still had "more than 30 bullets left" when he turned the gun on himself, the PM added. The school in Nonthaburi province is a local branch of the renowned Debsirin School, which in Thailand is widely associated with educational prestige. National police chief police general Kittiratt Phanphet told reporters that forensic officers had found the gunman's shots were quite accurate, with several hitting vital spots on the body. Authorities earlier warned people to stay away from the area and for those trapped in the building to hide and wait for rescuers. The Debsirin School, founded in Bangkok in 1885, is one of Thailand's top secondary schools with branches across the country. It counts many prominent Thai figures as its alumni, from diplomats and athletes to several prime ministers. A seventh-grade student, who fled the building, told the BBC that she was in class when she saw the gunman walking from room to room.