Hamburg - A gas leak at a school in the northern German state of Schleswig-Holstein injured 40 students and teachers on Monday, police said.

Emergency services evacuated between 350-400 students from the school complex in Bornhoeved after fumes of nitrous gas leaked into the buildings.

Students and teachers taken to nearby hospitals for treatment after complaining of headaches, muscle pain, nausea and throat irritation.

Nitrous gasses usually occur when plastic is burned.

"The fire department is looking for the source," a police spokesman said. (dpa)