A chemical tank ruptured in Washington state Tuesday morning, resulting in multiple fatalities and critical injuries, officials said, though the exact number of people impacted by the explosion was not immediately clear.

The incident occurred at the Nippon Dynawave Packaging Company in Longview, Washington, at approximately 7:15 a.m. local time. The tank contained white liquor, which is a mix of sodium hydroxide, sodium sulfide and disodium carbonate.

Authorities said nine people at the facility suffered injuries, including chemical burns, and were transported by ambulance to area hospitals, according to ABC News. The injuries ranged from critical to minor.

The cause of the rupture was not immediately clear but officials said there is no immediate threat to the surrounding community,

"The scene remains in the recovery phase as emergency responders continue operations," officials said in a joint statement. "Responding agencies continue coordinating closely with facility personnel and partner agencies as the investigation and recovery efforts continue."