Pakistani authorities say at least 19 people were injured when two car bombs exploded Wednesday, near the Pakistan - American cultural center in the port city of Karachi.

Police say the first bomb exploded outside the gate of the cultural center and injured one person. Minutes later, there was a second, more powerful blast as police and security officials were investigating. The second explosion injured several policemen and at least three journalists.

The cultural center, which was not damaged in the explosions, is near the residence of the U.S. consul general. Police cordoned off the area and ambulances rushed the injured to local hospitals.

Karachi -- Pakistan's largest city and its commercial hub -- has been a frequent scene of terrorist acts and other political and sectarian violence.

On Tuesday, an explosion at a shipping yard of the state-run Port Trust killed two people. Earlier this month, a suicide bomber killed 14 Shi'ite Muslims in an attack on a Karachi mosque during afternoon prayers.