ABUJA (Reuters) - Nigerian authorities said on Tuesday they had found a bomb-making factory near Abuja and had arrested six suspected members or people connected with the violent Islamist sect Boko Haram, including a foreign fighter from neighbour Niger.
Authorities are investigating a bombing of the U.N. headquarters on August 26 that killed 23 people in the Nigerian capital. Last week they arrested two suspected Boko Haram members over the attack and said they suspected a third member with an al Qaeda connection led the plot.
Department of State Services (DSS) spokeswoman Maryln Ogar told Reuters by telephone that the six detainees were not wanted in connection with the bombing of the U.N. building.
A statement from her office said the six were suspected of plotting and carrying out bombings on an electoral commission office on April 8, just before presidential elections, and of a church on July 10 -- both in the town of Suleja, just outside the capital Abuja. They were also wanted for the killing of four policemen.
"The five suspects all confessed that the main supplier of the explosive materials used for their bombing operations is a miner from Nasarawa State who the Service eventually arrested on 30th August, 2011," the statement said.
"A non-descript building where the improvised explosive devices (I.E.Ds) are assembled has been uncovered at an area popularly known as Chechnya, Hayin-Uku village," it said.
The statement listed what it called "the merchandise of death" found at the factory. It included a gas cylinder, three detonators, one attached to a battery, several pieces of detonators, shrapnel, batteries and cables.
Ogar said by telephone the suspects led authorities there.
"We found explosives at the sight as well. The suspects were the ones that took us there and showed us the things they use in putting these bombs together," she said.
Boko Haram, whose name means "Western education is sinful" in the northern Nigerian Hausa language, has become President Goodluck Jonathan's most intractable security challenge.
It has carried out frequent shootings or attacks with homemade bombs against security services and civilians in the remote northeast.
The U.N. bombing marks an increase in the sophistication of Boko Haram's attacks, possibly with better explosives, and an escalation from local to international targets, analysts say.
"There's no link between these suspects and the bombing of the U.N. building, based on their confessions," Ogar said.
Reporting by Camillus Eboh; Writing by and additional reporting by Tim Cocks, Editing by Rosalind Russell