Fire officials are investigating after a commercial building exploded Wednesday in Logan Township, New Jersey, injuring multiple people.

Four Savita Naturals employees inside the building were injured, and remain in critical condition, according to officials.

Witnesses told affiliate FOX 29 they felt the blast from hundreds of feet away.

One witness told the outlet he called 911 after seeing someone on fire emerge from the building.

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Gloucester County Emergency Management officials said the explosion caused extensive damage to the facility, as well as a neighboring building.

It is unclear what led to the explosion.

The incident is being investigated by multiple agencies, officials said.

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Fire and hazmat units are monitoring the burn off of additional fuel product stored on-site and continue to conduct air monitoring in the community.

Authorities initially asked residents and businesses within a two-mile radius of the explosion to shelter in place "until further notice."

As of 5 p.m. Wednesday, the shelter-in-place order was lifted.

This is a developing story. Please check back for updates.