Police and fire officials evacuated about 15 homes in the Edgewater community of Anne Arundel County early today after someone apparently dumped gasoline that caused an explosion in a storm sewer line.
Police said there were no reports of injuries or damage to homes.
About 40 people living on Oak Bluff Road off Londowntowne Road were evacuated. They were expected to be allowed back in their homes by noon, authorities said.
Other Oak Bluff Road residents were advised to stay indoors, said Capt. Gary Sheckells, a spokesman for the county Fire Department.
"Our belief is that someone is dumping gasoline in the sewer system," Captain Sheckells said.
Captain Sheckells said fire officials and officials with the Maryland Department of the Environment were flushing the sewer with thousands of gallons of water. The air in the area and in some homes was being monitored.
Residents said they heard what they thought was an explosion about 4:40 a.m. Police and fire officials then were called to the scene about 5:30 a.m., after a resident discovered that an Oak Bluff Road manhole cover was off.
Captain Sheckells said witnesses reported seeing someone running near a manhole.
Some residents told authorities that they had noticed a gasoline-like smell in the area.
Everett Armiger, of Oak Bluff Road, said he was awakened at about 5:30 a.m. by a firefighter. He said authorities had blocked off the street.