A loud bang from a chemical explosion near a new exhibit at the Smithsonian's National Zoo in Washington, D.C. resulted in no injuries, officials said.

"There was an incident related to chlorine on American Trail, near the otters and beavers," zoo spokeswoman Devin Murphy told The Washington Post. “There was a loud boom. No fire. No smoke.

“No humans were hurt. No animals were hurt. We cleared the area and DC fire is on scene and they’re investigating.”

Zoo spokeswoman Pamela Baker-Masson said a contractor working in a mechanical area next to the beaver and otter exhibits smelled chlorine and left the area Thursday morning. He later heard a bang. Baker-Masson said chlorine is kept in that area for water filtration.

Officials told The Post an employee may have been mixing chemicals improperly, leading to the explosion.

D.C. Fire and EMS hazmat units were called to the zoo just before 11:30 a.m., according to NBC4.

The Associated Press contributed to this report.