Philippine authorities are rethinking school safety measures and looking to expand civil defence planning to cover gun violence, officials said on Tuesday, a day after a deadly attack at a high school shocked a nation where such incidents are rare. At least three students were killed and 20 others injured when two of their schoolmates, aged 15 and 14, opened fire at a public high school in Tacloban City, southeast of Manila, on Monday. The attackers used a 9mm Glock pistol and a 38-calibre revolver.