MOBILE, Ala. (AP) -- A tank spewing potentially dangerous hydrogen peroxide vapors prompted firefighter to evacuate about 30 homes on two streets and close a city park in south Mobile Monday afternoon, fire authorities said.

No injuries were reported, but the evacuation order remained in force overnight as the tank continued to vent. It was not immediately known when the residents would be allowed to return home, said Steve Huffman, a spokesman for the Mobile Fire-Rescue Department. [...]

District Chief Douglas Cooper said peroxide vapors can ignite fires when they touch organic material.

The tank, containing about 1,000 gallons of hydrogen peroxide solution, is owned by a Georgia company but leased by the Mobile Area Water and Sewer System for water purification, Huffman said.

There was a hole in the screen over the tank's vent, Cooper said, which led him to believe an animal such as a squirrel may have chewed through and fallen into the tank. The animal's body would have been the organic material needed to raise the tank's temperature, causing it to vent. [...]