A series of explosions in Brooklyn Heights that sent five manhole covers flying into the air led to the evacuation of at least 10 buildings and shut down some subway service this afternoon.

There were no injuries and people have returned to the buildings.

“I thought a car bomb went off. That’s how loud it was,” said area resident Mary Goodman.

Emergency personnel said workers for National Grid, which supplies gas service to the area, may have struck a city telephone and electrical line while doing work near Joralemon Street and Columbia Place.

The blasts, which started just before 1 p.m., also sent fires and smoke pouring out of the manholes.

Due to the blast, there is no 4 train service in both directions between the Atlantic Avenue Station and the Brooklyn bridge-City Hall Station. 5 trains are running on the 2 line between the Nevins Street Station and the 149th Street-Grand Concourse Station in both directions, the MTA said.

Residents described a scene of confusion when the explosions happened. Some thought there was an attack on the subway system taking place.

“It sounded like a bomb went off,” said Suzanne Zumpano, who said the manholes flew about 10 to 15 feet into the air.