A member of the Joint Task Force (JTF) was Monday killed in an explosion in Maiduguri that left four others seriously injured.
It was learnt that an Improvised Explosive Device (IED) which was targeted at the task force patrol vehicle by suspected members of the Boko Haram exploded along the popular Lagos Street in the city, causing panic among residents of the town.
According to sources, the JTF men were on routine patrol in the area when the bomb went off around 8.am, which left the patrol vehicle badly damaged and in flame.
In another development, four people were said to have been shot dead on Sunday night by some gunmen in Damboa road area in Maiduguri.
The sect also said it will target female government officials.
It said between seven and 10 spouses of the group's members are being held by security operatives.
In a short video released on YouTube Monday its leader Abubakar Shekau, said the group was aware of what would be going on where the spouses of the members are held.
Shekau, who also vowed that the group would launch attacks to protest the release of an anti-Islam video on YouTuba, said: "As at Saturday, when I made this video, between seven and 10 of them (women) have been incarcerated.
"We don't know where they are kept or what they are doing to them. But as Muslims, we know what unbelievers do to women. Now, married women are victims of state terror."
Shekau also promised hard times for political and traditional rulers of Northern origin. Among those the group threatened to attack in the video were governors, emirs and others in positions of authority.
The grouse of the group is that they have betrayed the people.
Shekau said: "This message is for those in authority.
"Wallahi you have no resting place again and no resting time again. Either we are here or we are not. You have messed up yourselves and you have messed up your own situation."
Shekau also denied that the group was negotiating with the government.
He said: "The claim that we are negotiating with the state is untrue. That is the figment of their imagination. We are not in dialogue with anyone.
Shekau admitted that the spokesman of the group, Abu Qaqa, has been captured by security operatives and that he was in the custody of the State Security Service (SSS).
"The most outrageous of the claims is that they have killed some of our leaders or have arrested some of our leaders."
He said if the leadership of any group was killed, it must be the one created by the government.