Kano (Nigeria): An explosion on Saturday at a house allegedly used to make home-made bombs in Nigeria's northeastern city of Maiduguri killed three suspected Islamist sect members, the military said.
   
Lieutenant Colonel Hassan Mohammed, spokesman of a special force deployed in the city, said "the house was used by suspected members of Boko Haram sect as major factory for the production of improvised explosive devices."
   
He said three "mutilated corpses" were found, adding: "It was clear the suspects were killed in the process of making improvised explosive devices."
   
Maiduguri has been the epicentre of a wave of attacks in northern Nigeria blamed on Boko Haram.
   
The sect on Saturday threatened to launch attacks on northern Nigeria's largest city Kano if security forces continued to arrest its members.
   
Sect leader Abubakar Shekau claimed in the letter sent to the Kano state government and the media that Boko Haram members have been arrested over the past five months on the pretext that they were thieves and armed robbers.

"We are therefore compelled to write this letter to inform Kano residents of this development so that when we launch attacks in the city as we have been doing in Maiduguri, they should not blame us," Shekau said in a letter emailed from an address previously used by the sect.
   
The threat comes after two attacks targeting the military and the police killed at least four members of the security forces in Kano.
   
Gunmen on Thursday attacked a military-run school outside the city, killing at least three air force personnel.
   
And on Friday, gunmen opened fire on a police checkpoint on the outskirts of the city, resulting in a shootout which left one policeman dead and another seriously wounded, Kano state police spokesman Magaji Majia said.
   
Mohammed said large quantities of rifles, ammunition and material used in the production of home-made bombs were found at the Maiduguri house after the blast.

(Agencies)