An explosion at an oil refinery in Ohio on Saturday blew out windows in nearby homes, but no injuries were reported.

The explosion happened in a processing unit of the Husky Lima Refinery where crude oil is heated to begin the process of breaking it down into other products, CBS News reported.

About 20 homeowners reported that their windows were broken in the explosion, which occurred at 6:00 a.m. and could be felt at least 10 miles away. The blast caused a fire that sent black smoke into the air above the refinery and continued to burn until it was eventually put out at 8:25 p.m., according to Heidi Griesmer, a spokeswoman for the Ohio Environmental Protection Agency.

Officials monitored the air for contaminants including benzene, carbon monoxide, sulfur dioxide, hydrogen cyanide, hydrogen sulfide and asbestos, but tests did not detect anything hazardous in the first hours after the explosion, Griesmer added. Further tests will be conducted over the course of this week.

The refinery in Lima produces various oil-based products, including gasoline, diesel and jet fuel.

Canada-based Husky Energy said on Monday that the impact of the incident was limited to the isocracker unit and the site was secure. All employees from the site are accounted for and there were no injuries.

As a precaution, other facilities and units at the refinery were shut down and production is expected to remain suspended for about one week.

However, the refinery can operate without the isocracker unit, which processes about 25,000 barrels per day, and the company is making plans to resume operations.

Supplies to customers should not be affected by the outage, Husky Energy confirmed.