Hundreds of passengers have been evacuated from Hamburg Airport after 68 people were injured by a toxin believed to be spreading through the airport's air conditioning system.

All flights were suspended from 11.30am but resumed shortly before 2pm.

A corrosive substance is believed to have been discharged in an area where passenger luggage is scanned by security staff and travellers have been complaining about breathing problems, burning eyes and nausea.

In a statement, the airport said firefighters concluded the substance was likely to be pepper spray. The investigation continues to determine how it got into the airport's air conditioning system.

Earlier today, spokeswoman for the airport, Karen Stein, said: "We're working closely together with the authorities to find out more.

"We have cancelled all flights at least until 2pm, and most parts of the airport have been evacuated."

People evacuated from the airport had to wait outside the terminals in freezing temperatures but they were quickly allowed back in, a police spokeswoman said.

Doctors were examining those injured by the unknown toxin in a specially designated area outside the airport.