A failed former student, dressed in black and bent on revenge, yesterday shot dead 17 people, including 14 teachers, a policeman and two girl pupils in Germany's worst school shooting.

A failed former student, dressed in black and bent on revenge, yesterday shot dead 17 people, including 14 teachers, a policeman and two girl pupils in Germany's worst school shooting.

The 19-year-old former pupil at the Johann Gutenberg grammar school, in the eastern city of Erfurt, later killed himself as police approached the classroom where he had locked himself, alone, after the rampage.

Police described a scene of horror, the victims' bodies scattered in bathrooms and corridors where they fell during their attempts to escape the gunman.

The bloodbath was the worst school shooting since the 1996 Dunblane massacre, that left 16 children and their teacher dead at a primary school in Scotland. In the Columbine shooting in 1999 in the United States, two students, also dressed in black and firing indiscriminately, killed 13 people and then themselves.

Chancellor Gerhard Schröder said he was "stunned by this horrible crime", which was the second fatal gun attack in a German school this year.

The school caretaker called police yesterday at 11.05am yesterday to report that someone was shooting at people.

Students reported that they saw a masked man dressed in black entering the school, which has 700 pupils aged between 10 and 19 and is situated in a residential area of the city.

Police said the gunman fired wildly after entering the school. Shooting continued intermittently for about half an hour until police commandos entered the building and the gunman retreated to a classroom. He shot himself when he realised his situation was desperate. Filip Nieman, a student who was working in a nearby classroom said: "The teacher let us go out and see what was happening and when we left the classroom, three to four metres in front of us, there was a masked person in black holding his gun.

"He stretched out his gun and shot. We saw a teacher fall to the ground. We just turned and ran. I heard from other kids the gunmen opened classroom doors and aimed at teachers."

Initially it was thought that there were two gunmen, carrying a pump-action gun and a handgun, but police established that the former student, who had been expelled several weeks ago, had acted alone.

Police and armed special forces teams spent four hours trying to make contact with the gunman. One student wrote "help" on a piece of card and held it up against a window. Others called family and friends on their mobile phones.

Emergency services moved in to deal with the injured while parents and friends gathered as close to the school as police would allow them.

The German President Johannes Rau said the event was "inconceivable".

"Germany is mourning an incomprehensible event. We cannot find the words to express what we in Germany are feeling."

In February, a 22-year-old German who had lost his job shot dead two former bosses and his former high school principal in a rampage outside Munich.