At least one person died and four remain missing after an explosion struck a German industrial park that is home to more than 30 chemical companies.
Officials in the city of Leverkusen said 31 people were injured in the blast, which happened at 09:40am local time.
The explosion triggered a fire that took over three hours to put out. Plumes of black smoke were seen in the area.
Police have told local residents to stay inside and close windows and doors. The cause of the blast is not yet known.
“We are deeply saddened by this tragic accident and the death of an employee,” Lars Friedrich, head of Chempark said.
Rescuers are searching for the missing.
Five of the injuries are serious enough to need intensive care, police said. All of those affected worked at the site.
Three tanks at the site were completely or partially destroyed, making it hard to determine where the explosion happened.
The sound of the blast could be heard several kilometers away. Police sealed off the surrounding area and closed a number of motorways nearby.
City Mayor Uwe Richrath said it was a “dark day for the people of Leverkusen”.
Playgrounds in two nearby neighborhoods have been closed and residents have been told to rinse fruit and vegetables from their gardens before eating them.
However, the city of Leverkusen said any measures taken were just as a precaution and pollution levels were still “in the green”.
Leverkusen is less than 50km from a region hit last week by catastrophic floods that killed at least 180 people.