5 missing, 16 wounded in blast at German chemical hub

According to initial details, after the blast, a large black cloud rose into the air.

The explosion happened at 9.40 a.m. local time, causing a fire at a fuel depot at Chempark, an industrial park for chemicals companies including Bayer and Lanxess.

German officials classified the explosion as “an extreme threat” and asked residents to stay inside, turn off ventilation systems and keep windows and doors closed.

However, the fire department tweeted that measurements of the air's pollution “do not show any kind of abnormality.”

They said the smoke had gone down but that they would continue to measure the air for toxins.

The city of Leverkusen said in a statement that the explosion at the Chempark site, about 20 kilometres (13 miles) north of Cologne on the Rhine river occurred in storage tanks for solvents.

Police in nearby Cologne said a large number of officers, firefighters, helicopters and ambulances from across the region had been deployed to the scene.

More than 30 companies operate at the Chempark site in Leverkusen, including Covestro, Bayer, Lanxess and Arlanxeo.