Explosions hit a federal police building and a residential area of the eastern city of Lahore on Tuesday, killing at least 20 people, police said.

One blast devastated the downtown police office, killing at least a dozen people, said Mohammed Afzal, a city police official. A second blast wounded several people in an upscale residential district, said Mohammed Abbas, another police official.

The cause of the explosions was not immediately clear.

Private TV footage showed the badly damaged facade of the police office, a large, multiple-story concrete building, with rubble scattered across an intersection. Flames shot up from part of the wreckage and several cars were damaged.

An ambulance wove through a crowd of hundreds of bystanders — some with torn clothes, others with minor wounds — stumbling away from the blast scene.

PHOTO CAPTION

Pakistan map locating Lahore