Abuja - Nigerian authorities said on Friday they had arrested two people suspected to be the masterminds of a double suicide bombing against a military church in the northern city of Kaduna late last year that killed 15 people.
Two suicide car bombers struck the church at a military barracks on November 25, an attack blamed on radical Islamist sect Boko Haram.
At least 30 people were wounded in the blasts, which embarrassed the military and led to the sacking of a high ranking officer.
Boko Haram killed hundreds last year in a campaign to impose sharia, or Islamic law, on religiously mixed Nigeria.
The sect's violence has been sporadic but hugely destabilizing in the impoverished north, making it the top security threat to Africa's leading energy producer.
"Following the incident, a thorough investigation was initiated by this service and the military which led to the arrest of some suspected masterminds of the attack," spokeswoman for Nigeria's secret service Marilyn Ogar said in a statement.
She named Ibrahim Mohammed, an 18-year-old, and Mohammed Ibrahim Idris, a 50-year-old street trader, as the two suspects. Others were also being questioned.
"Mohammed and Idris will be handed over to the military for further investigation. However, other suspects apprehended in the same vein are still being ... (questioned)."
Mohammed Zingina, a senior Boko Haram commander accused of organizing several suicide bombings, was captured on Sunday in the northeastern city of Maiduguri, where the sect has its headquarters.
He had been on a most wanted list, with a bounty of 25 million naira ($160,000) for information leading to his arrest. ($1 = 157.0500 naira)