A fire at a furniture factory near the Egyptian capital of Cairo killed 25 people and injured 22, the country’s health ministry said on Tuesday. The factory was reportedly operating without a government safety certificate.

The blaze in the city of al-Obour is thought to have begun after a gas canister exploded while it was being transported in an elevator, security officials said. The factory’s owner and a number of other officials linked to the fire were detained.

“We were starting to work this morning when we heard a huge explosion from the factory on the floor below us,” local employee Islam Yousri said, according to Euronews.

“They work using chemicals and have oxygen tanks. One of them blew up and – with the mixture of the chemicals – there was an explosion in the whole building.”

Health Ministry spokesman Hossam Abdel-Ghaffar said the government had declared a local “state of emergency” and that the victims had been taken to local hospitals, according to the Associated Press.

Incidents like these are reportedly common in Egypt, due to lax safety standards and aging infrastructure. 

A separate fire at an Alexandria food market left 11 people injured on Tuesday, the BBC reported.