Police are investigating the incident at the vocational college in Athens
A Greek student has died after shooting a fellow student and two passers-by at his college in Athens before turning the gun on himself.
Police said the gunman's motive was revenge, saying he had left a note indicating he was tired of being mocked by fellow pupils.
The wounded student is in a serious condition in hospital. The other two victims have minor injuries.
The shooting happened at a vocational college in a poor district of Athens.
School shootings are rare in Greece and the incident has stunned Greeks, the BBC's Malcolm Brabant in Athens says.
'Motive was revenge'
The gunman has been identified in local media as 19-year-old Dimitris Tachmanidis, who was studying car electronics at the Hellenic Manpower Organisation's (OAED) vocational school.
Witnesses said he walked into the college - which offers vocational training for students - on Friday morning with two pistols.
He was said to have been heading for the classrooms, but as he mounted the stairs he fired at least three shots at a 19-year-old student heading towards him.
The gunman then turned to leave the school and was confronted by two workers from a nearby factory, witnesses said.
He shot at the two men before running across the road and shooting himself in the head.
"He succumbed during the operation to save him," senior health ministry official Panayiotis Efstathiou said.
Mr Efstathiou said the other student had been shot in the chest, arms and legs and remained in a serious condition.
According to one of the gunman's friends, he was a very quiet youth who was tired of being mocked by other pupils.
"He left a note saying he couldn't take it any more," police spokesman Panayiotis Stathis told The Associated Press. "It seems his motive was revenge."