Nigerian soldiers raided an Islamist bomb-making factory just outside the north's biggest city of Kano on Wednesday, seizing guns, fertilizer and equipment for assembling suicide vests, the military said.
Kano has been relatively quiet for much of this year, as Islamist sect Boko Haram focuses its fight for an Islamic state on its heartland in the northeast.
However, Kano, historically a hub for trade across the Sahara, has been periodically attacked by the sect. A bomb blast in a bus park, in an area predominantly inhabited by Igbo Christians from the south, killed at least 15 in July.
Brigadier General Ilyasu Abbah, a Nigerian army commander in Kano, told journalists Boko Haram fighters had fled by the time his troops arrived at a house in the village of Gunduwawa.
"The materials used for making IEDs were found. They were manufacturing the weapons there. We also found three ... IEDs (improvised explosive devices), one primed explosive suicide backpack and 18 empty IED cylinders," he said.
They also found 24 detonators, fertilizer, remote controls, automatic weapons and hundreds of rounds of ammunition.
He said intelligence reports suggested those who had amassed the weapons planned to disrupt celebrations for an upcoming Muslim holiday.
Despite a concerted military offensive since May aimed at trying to crush Boko Haram, the Islamist group remains the biggest security threat to Nigeria, Africa's top energy producer.
Over the past week, Nigerian fighter jets have bombed suspected Boko Haram camps in the country's northeast in response to a massacre of students at an agricultural college that killed at least 40.