Toxic smoke from a massive smoldering fire has triggered an evacuation in the Port of Antwerp. Firefighters are still battling the blaze, which produces “poisonous substances,” according to officials.

Some 5,000 tons of nickel sulfide caught fire in a warehouse of one of Europe’s largest seaports, the Port of Antwerp, on Saturday afternoon.

The smoke from the blaze, which engulfed a large area, may cause irritation and odor nuisance, police say.

“Poisonous substances have been released in the immediate vicinity of the seat of the fire,” the spokeswoman of the Antwerp Fire Department, Jasmien O, said as cited by local outlet Het Laatste Nieuws.

Alle hulpdiensten werken samen om deze #smeulbrand onder controle te krijgen. De grote hoeveelheid en de aard van de stof maken het moeilijk om te blussen. Er kan mogelijk geurhinder zijn in Ekeren, Kapellen en Stabroek. Alle info via de website en via het infonummer 1771. https://t.co/XTopHpj3KC — Brandweer Zone Antwerpen (@BZAntwerpen) August 12, 2018

As the operation to extinguish the fire continues, authorities have introduced special safety measures in the area. Companies and vessels in a 1.8-kilometer perimeter were evacuated. Inland navigation and car traffic in the vicinity of the site have also been stopped.

Update #smeulbrand: Dit is de zone van bedrijven die momenteel geëvacueerd wordt in de #haven. Woon of werk je hierbuiten, dan is de hinder wellicht beperkt. Toch last van geur of rook? Sluit dan ramen en deuren en schakel ventilatie uit. pic.twitter.com/Asix2ayL7q — Brandweer Zone Antwerpen (@BZAntwerpen) August 12, 2018

Police advise locals to shut doors and windows and switch off ventilation in houses and cars and seek medical assistance if they feel symptoms of intoxication, including burning eyes or coughing.

Rampenplan in werking na grote brand in haven Antwerpen https://t.co/79ecIsMSZFpic.twitter.com/FVqVJQq8dy — PZC (@pzcredactie) August 12, 2018