KANO, Nigeria: Nigeria's top Islamic leader has called on President Goodluck Jonathan to offer amnesty to all combatants linked to an extremist group that has killed hundreds, in comments obtained Wednesday.

Addressing a key religious body in the northern city of Kaduna, the Sultan of Sokoto, Muhammad Sa'ad Abubakar, said Muslim leaders were "very, very concerned" about unrest in the country where Boko Haram Islamists have carried out scores of attacks in the mainly Muslim north.

"We want to use this opportunity to call on the government, especially Mr President, to see how he can declare total amnesty to all combatants without thinking twice," Abubakar said.

"Even if it is one person who is a terrorist and he denounces terrorism it is the duty of the government to accept that one person and see how he can be used to reach others."

Boko Haram has said it is fighting to create an Islamic state in northern Nigeria, but the group is thought to have many different factions, including a hardcore leadership cell.

Experts say that many of its young combatants have turned to violence because of government corruption and crippling poverty in the north, which is poorer than the mostly Christian south.

"If there is amnesty declared we believe so many of those young men who have been tired of running and hiding will come out and embrace that amnesty," said Abubakar.

The sultan served in Nigeria's military for three decades before assuming the revered religious post in 2006.

Boko Haram has carried out attacks on three senior Nigerian Muslim leaders, who they accuse of betraying Islam by working with the government.

Abubakar referred to unconfirmed reports that Jonathan plans to make his first visit as president to the embattled northeastern city of Maiduguri, considered Boko Haram's home base.

The sultan indicated Jonathan's trip could provide an opportunity to launch a peace drive.

Several past attempts to negotiate with Boko Haram have led nowhere.

In a video obtained Tuesday, the group's suspected leader Abubakar Shekau said Boko Haram would not enter dialogue with the government so long as its members were being arrested and detained, a condition cited in previous statements.

Violence linked to Boko Haram's insurgency in northern and central Nigeria has led to the deaths of some 3,000 people since 2009, including killings by the security forces.