Nigeria's army has offered 290 million naira ($1.8 million) for information leading to the capture of 19 leading members of Islamist sect Boko Haram, whose insurgency has killed hundreds this year.
Boko Haram wants to impose strict sharia - or Islamic law - in the country of 160 million, split roughly equally between Christians and Muslims, and the group has become the biggest security threat to Africa's largest oil producer.
The military Joint Task Force (JTF) in northeast Borno state, the sect's home territory and the focus of its attacks, offered a reward of 50 million naira for the sect's self-proclaimed leader Abubakar Shekau.
It offered 25 million naira for each of the men said by the JTF to be his main commanders: Habibu Yusuk, Khalis Albarnawai, Momodu Bama and Mohammed Zangina, and 10 million naira for 14 other senior members.
"They are wanted in connection with terrorist activities particularly in the north east zone," a statement by the JTF in Maiduguri, Borno's capital, said on Saturday.
"(This) led to the killings, bombings and assassination of civilians, religious leaders, traditional rulers, businessmen, politicians, civil servants and security personnel."
Boko Haram's core group, believed to be led by Shekau, still focuses its attacks in its northeast base but the group is split into different factions spread across the north of Africa's most populous nation.
It has carried out several attacks in the capital Abuja, including a suicide car bombing on the United Nations headquarters last year that killed at least 24 people.
Britain last week banned a Nigerian Islamist group known as Ansaru it said was aligned with al Qaeda and was probably responsible for the killing of a Briton and an Italian kidnapped in northern Nigeria last year.
At the time of their deaths, a senior Nigerian security official said the captors belonged to a faction of Boko Haram.
Boko Haram has largely had a domestic agenda but Western governments are increasing worried about Islamists in northern Nigeria linking up with outside jihadist groups such as al Qaeda's north African wing.