Several children are said to have been injured after a "mass casualty incident" with tear gas at a primary school in Berlin.

The local fire department descended on the Miriam-Makeba-Grundschule, on the German capital's Zinzendorfstrasse, at 9.04am local time on Friday.

As many as 37 students were injured in the incident, according to German media reports, with scores of concerned parents rushing to gather outside the building.

While Berlin's police department said "at least 10" children were complaining of eye and respiratory irritations.

Berlin's police department said 'at least 10' children were complaining of eye and respiratory irritations (file photo)

Further local reports say that tear gas had been sprayed in a hallway at the school.

"One child had to be transported to a hospital for further medical care," the fire department said.

According to a police spokeswoman, after the building had been thoroughly ventilated, there was no further danger to students and teachers.

Staff later decided to cancel lessons on Friday, with all students allowed to go home.

Berlin Police said at around 11.30am local time: "At least 10 children are reportedly complaining of eye and respiratory irritation.

"They are currently being treated by emergency personnel. The building has been evacuated and ventilated.

"Currently, there is no longer any danger. School operations are to be suspended.

"Investigations into the cause and possible perpetrators are ongoing."

Tear gas, if inhaled or introduced to the body, can lead to serious injuries including blindness, glaucoma, and even death.

Young children, particularly those with asthma or respiratory problems, can be at risk of more severe complications from the spray.