Amtrak has said that Union Station in Washington was evacuated and shut down for a more than an hour Sunday after a report of an unusual odor.

Amtrak said in a news release that Washington fire officials asked Amtrak to close the busy station at 1:45 p. m. EDT. Amtrak also said that fire department personnel discovered the suspect smell was caused by a malfunction in some batteries in an equipment closet and service resumed at about 3 p. m. ET.

CNN further reported that Washington Metro Area Transit Authority officials said subway trains did not stop at Union Station during the shutdown but service was not otherwise interrupted. "Some slight delays" in its service would be resolved by late Sunday afternoon, Amtrak said.

The odor was described as something like natural gas or sulfur, fire department spokesman Peter Piringer told CNN. No injuries were reported. (With Inputs from Agencies)