Souleymane Brahim said today the first explosion hit N'Djamena early in the morning, followed by a second one. He said gunfire was heard after the explosions.
Several residents confirmed that they saw at least 11 bodies, including five police officers.
More details were not immediately available. Officials have not yet commented on the explosions.
The blasts come weeks after a double suicide bombing in the capital that killed at least 38 people. Police yesterday announced the arrests of 60 people for those bombings.