MOSCOW (Reuters) -A gunman with a swastika on his teeshirt killed 15 people, including 11 children, and wounded 24 at a school in Russia on Monday before committing suicide, investigators said. The attacker, a man in his early thirties who was named by authorities as Artem Kazantsev, killed two security guards and then opened fire on students and teachers at School Number 88 in Izhevsk, where he had once been a pupil. Russia’s Investigative Committee, which handles major crimes, said it was looking into the perpetrator’s suspected neo-Nazi links. “Currently investigators…are conducting a sea…