ATHENS, Greece (CNN) -- A man, apparently upset at the way his fellow students had been treating him, opened fire outside a training center for the unemployed in Athens on Friday, police said.
The gunman wounded three people before fatally shooting himself in the head, authorities said.
The man, believed to be about 18, first approached another student of the center Friday morning.
The two exchanged words before the gunman shot him in the chest, police said.
The gunman then walked toward the center's gates and was accosted by two staffers. He fired again, hitting both employees -- one on the hand and the other in the foot. He then pointed the gun at his head and fired, police said.
All three victims have been hospitalized, with the first victim in critical condition, authorities said.
Officials said the man left a note in his bag saying he was tired of being teased by others who were enrolled at the center, and had vowed to take revenge. Police also found a knife in the bag.
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