|More than 100 people were killed in attacks by Boko Haram in Kano on January 21 [Reuters]
A spokesman for the Islamist group Boko Haram has rejected a call by Nigerian President Goodluck Jonathan for talks and threatened fresh attacks, if captured members of his group were not freed.
"They should expect imminent attacks on Sokoto [a northwestern city] if they don't release our members," Abul Qaqa said on Saturday.
President Jonathan has faced intense criticism for his failure to contain Boko Haram and in a media interview with Reuters news agency this week he urged the group to state its demands and begin dialogue.
"If they clearly identify themselves now and say this is the reason why we are resisting... then there will be a basis for dialogue," Jonathan said in an interview with the Reuters news agency in the capital, Abuja, on Thursday.
However in rejection to Jonathan's call, Qaqa said in a conference call with journalists in the northern city of Maiduguri, "we don't think dialogue is possible under the current situation."
Qaqa cited a government assault on its members as reason for not engaging in talks.
"The same day Goodluck Jonathan... said we should come out for dialogue, security agents in Sokoto arrested a large number of our members in raids on their homes," he said.
Qaqa said the group "will launch attacks in Sokoto similar to the big Kano attacks," if captured members of the group were not released.
The January 20 attacks in Kano that killed 185 were the deadliest yet claimed by the group, whose assaults appear to be increasingly daring and have plunged Nigeria into a security crisis in several northern areas.
In a message posted on the Internet, Boko Haram's purported leader, Abubakar Muhammad Shekau, said he had ordered those attacks because the government had tortured and illegally detained the group's members.
Nigerian police raided an alleged Boko Haram hideout in Sokoto city on December 21, killing one suspect and arresting three others, according to a police account.
Qaqa said the government had also arrested Boko Haram loyalists in Sokoto, which is the capital of a state of the same name.
In August, gunmen attacked a police station in Tambuwal, a town in Sokoto state, killing four policemen and two civilians.
Many of Boko Haram's recent attacks have struck police targets.