About 30 others were injured in the blasts, which happened shortly after midday at the St. Andrew Military Protestant Church, a spokesman for the Army said.
Witnesses said one of the car bombs was driven into the church soon after service but was thought to have caused no casualty.
Then the second car which was parked outside the building detonated minutes later as worshipers gathered around the debris left by the first explosion.
“There were twin suicide bombings today at the St. Andrew Military Protestant Church, Jaji Military cantonment at 1205 and 1215 hours,” director of Army Public Relations, Brigadier General Koleso, said in a text message.
“A bus first ran into the church and exploded about five minutes after service, while a Toyota Camry parked outside the church detonated ten minutes later.
“Casualties are 11 dead and about 30 injured. The injured are receiving treatment on Military hospitals both in Jaji and Kaduna.”
Yesterday’s attack was the second on a military base in Kaduna this year, coming after the suicide bombing at the headquarters of the 1 Mechanised Division in February.
Soon after the attack, the Armed Forces Command and Staff College was cordoned off and our correspondents could not get into the premises.
Even officials of the National Emergency Agency (NEMA) and Red Cross were prevented from entering the cantonment to render assistance to the victims of the blasts. The officials told Daily Trust in Kaduna that they were turned back by soldiers on arrival at the gate.
Sources at the military hospital in the Jaji told Daily Trust that more than a dozen dead bodies as well as many injured people were brought.
“Honestly, the attack is devastating….this place is overwhelmed by corpses and injured persons. In fact, I am not in the mood of talking because as I talk to you now I counted over eight corpses,” the source said.
“Many people have also sustained grievous injuries that we cannot handle here. Nevertheless, we are trying to stabilise them before we move them to either 44 Army Reference Hospital or Ahmadu Bello University Teaching Hospital in Zaria,” the source added.
Another source told our correspondents that the blasts have caused panic in the Jaji military barracks.
“I was sitting in my room when I heard a heavy sound. Not long after that I heard another blast. The two blasts have caused panic here. People were shocked because all the nearby buildings were affected by the twin blasts. The thunderous sound of the blasts also made people to be confused. People at the church and in the barracks ran helter-skelter for safety. This is a place where bomb blast is least expected,” the source said.
A military spokesman told the BBC two vehicles were driven into the barracks in Jaji in what he described as “surprising and an embarrassment”.
“The first blast caused no casualties and curious worshippers gathered around the scene looking at the debris... and that was when the second blast happened,” the unnamed military spokesman said.
No one claimed responsibility for yesterday’s bombing in Kaduna, which has seen similar deadly attacks in the past that were blamed on the Boko Haram sect.
On February 7, a suicide bomber rammed into the headquarters of the 1 Mechanised Division in Kawo, damaging the administrative building.
At least 50 people were killed in bombings in Kaduna in June and the reprisals that followed.
On October 28, seven people died in a suicide bombing at the St. Rita’s Catholic Church in Kaduna, sparking another reprisal that left two people dead.
On Friday, the Joint Task Force in Maiduguri offered a reward of N50 million for help in tracking down Boko Haram leader Abubakar Shekau, and N10 million each for other suspected leaders of the group.
In his reaction to yesterday’s attack, Kaduna State Governor Patrick Yakowa said through his spokesman Reuben Buhari: “No matter what happened, we are convinced that evil will never triumph over good for ever, and as such, we call on all people of the state to continue to cooperate with the government and all security agencies to prevent incidents like this, and we pray that quick healing will come upon those injured.”
The Northern States Governors Forum described the attack as cruel and wicked. Chairman of the forum and Governor of Niger State, Dr Mu’azu Babangida Aliyu, said in a statement by spokesman Danladi Ndayebo that the deceased were heroes who died in the course of service to the fatherland.
The forum reiterated its commitment to continue to work closely with the Federal Government in finding a lasting solution to the security challenges confronting the nation.
For his part, Senate President David, in a statement by his press secretary Paul Mumeh, said, “We have more to gain by being our brothers’ keeper. Security operatives to step up to the challenge. This a challenge to all irrespective of religious, ethnic or political learning. It is about the survival of Nigeria.”
Speaker of the House of Representatives Aminu Waziri Tambuwal also condemned the bombings and urged security agencies not to despair.
He said no religion condones attack on innocent worshippers, and urged all those behind the bombings to stop forthwith. A statement by his spokesman Imam Imam quoted Tambuwal as restating the commitment of the House of Representatives to assist security agencies to tackle the insecurity in the country.