An explosion at an industrial park for chemical companies in Germany has killed at least five people.
Rescue teams in western Germany say there is no hope of finding any more survivors after a deadly explosion at a chemical park in the city of Leverkusen.
At least five people were killed and 31 others injured in the blast at the industrial park near Cologne.
Three people were "seriously" injured -- one in a "life-threatening condition" -- while two workers remain missing, the municipality has said.
On Thursday, rescue workers recovered the bodies of three workers from the chemical manufacturing site.
"My thoughts go to the injured and their relatives. The search for the missing is still going on at full speed. Unfortunately, the hope of finding them alive is fading, ” said the site operator's manager Lars Friedrich.
Currenta, which operates the Chempark industrial park, said in a statement that the missing employees likely did not survive the accident and they expected the death toll to rise to seven.
"We have to assume that the missing people can no longer be found alive," CEO Frank Hyldmar had told reporters in Leverkusen.
The explosion took place at around 09:30 CEST at a waste incineration plant in Leverkusen, a city in the western North Rhine-Westphalia region. The cause of the explosion remains unclear.
The municipality said that a storage tank of solvents was on fire, but said that the blaze had been extinguished after four hours.
Around 360 emergency services staff were deployed to assist local authorities, the municipality said, while several major roads nearby were also partially closed.
Germany’s Federal Office for Civil Protection and Disaster Assistance had classified the explosion as "an extreme threat".
After the explosion sent a large black cloud into the air, residents in Bürrig district -- where the Chempark is located -- were asked to stay indoors.
Local fire services said that had been testing the air throughout the city for toxins but said that they remained "inconspicuous," and the area has been given the all-clear.
But residents have still been advised to avoid carrying soot particles into their homes and remove footwear outdoors.
Leverkusen is home to Bayer, one of Germany's biggest chemical companies.