Militants targeted army's and air-force bases in Nigeria as explosions hit northern city of Kaduna on Tuesday, even as casualty figures remain unknown.
Spokesman for the National Emergency Management Agency (NEMA), Yushau Shuaib told the media that the incident which happened almost simultaneously took everybody unawares.
"One of the bombings occurred inside the 1st Mechanised Division of the Nigerian army located at Kawo, an outskirt of the city while another exploded near a bridge inside Kaduna," he said.
A source said a suicide bomber who wore a military uniform had attempted driving into the military base but was shot at by soldiers standing on guard at the gate when he refused to heed an order to stop.
Another attack took place at an air force base at a peripheral town of Mando but no personnel were available to explain the extent of damage. Kaduna state police commissioner, Bala Nasarawa confirmed the attacks but gave no further details.
Islamist group Boko Haram has been blamed for scores of bomb attacks in northern Nigeria.