A teenage gunman who wounded three people at a college in Greece and killed himself had warned of the attack hours earlier on an Internet posting that included photographs of him posing with weapons, police said. The 19-year-old man, armed with two handguns and a knife, opened fire at the vocational training college in western Athens and then shot himself in the head, authorities said. He died in hospital several hours later. One student was shot in the chest and seriously wounded and two men were shot outside the building and suffered lighter injuries, police and Health Ministry officials said. The gunman left a note accusing his fellow students of picking on him, and posted the message on a social networking site. "I have no reason to continue living. But, unluckily for you, I'm too selfish to leave and let you keep living ... ," he said in the note which was written in Greek.