Kano - The leader of Nigeria's Ansaru jihadist group, a Boko Haram splinter group ideologically aligned to al-Qaeda in the Islamic Maghreb, has been arrested, an army spokesman said on Sunday.
Khalid al-Barnawi is one of three Nigerians listed by Washington in 2012 as "specially designated global terrorists".
The US Department of State in June 2012 named Barnawi alongside Boko Haram leader Abubakar Shekau and Ansaru founder Abubakar Adam Kambar as terrorists.
"Security agents made a breakthrough on Friday in the fight against terrorism by arresting Khalid al-Barnawi, the leader of Ansaru terrorist group in Lokoja," military spokesman Brigadier General Rabe Abubakar said.
"He is among those on top of the list of our wanted terrorists," he added.
"Shekau is the most visible leader of the Nigeria-based militant group Jama'atu Ahlis Sunna Lidda'awati Wal-Jihad, commonly referred to as Boko Haram," the US state department said 2012.
"Khalid al-Barnawi and Abubakar Adam Kambar have ties to Boko Haram and have close links to al-Qaeda in the Islamic Maghreb," it said in a statement.
Al-Barnawi assumed the leadership of Ansaru following the death of Kambar in a military raid on his hideout in Kano in March 2012.
"We are very happy about this development (arrest). It is a great breakthrough in our fight against insurgency in the country," Information Minister Lai Mohammed said.
A serving army officer added that his arrest was "a huge succees and will have a profound effect on counter-terrorism operations in Nigeria and beyond".
"He is a known transnational terrorist and the backbone of all Al-Qaeda affiliate groups in west Africa," the officer, who asked not to be named, revealed.
Ansaru, a splinter group of Boko Haram, specialising in high profile killings and attacks on global interests, is also linked to Al-Qaeda in the Islamic Maghreb.
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Barnawi, 47, whose real name is Usman Umar Abubakar, hailed from Biu town in Borno state.
He and his group have been involved in a string of kidnappings of mostly foreigners.
The group comprises mostly western-educated Boko Haram members who were trained in AQIM camps in the Algerian desert.
They disapproved of Boko Haram's indiscriminate bombing and shooting campaign, preferring instead high profile killings and attacks on western interests.
Kamber and al-Barnawi were both former close allies of the late Boko Haram sect leader Mohammed Yusuf.
Al-Barnawi was the alleged mastermind of the 2011 kidnap of a Briton and an Italian, both construction engineers, in Kebbi state.
The two hostages were killed in a failed rescue bid by British and Nigerian Special Forces in the northern city of Sokoto in 2012.
Trained in Afghanistan and Algeria, he was also behind the 2012 kidnap of a German construction engineer - Edgar Raupach - in Kano.
The German was killed along with four captors in a botched rescue operation by Nigerian troops the same year at a hideout on the outskirts of Kano, where the group is mostly based.
Ansaru also claimed a 2012 attack on a maximum security facility in Abuja where detained Islamists were being held, killing two policemen and freeing 40 inmates.
With the emergence of Ansaru, Barnawi's faction became independent of Boko Haram but still maintained ties.
The group also claimed responsibility for the kidnap of a French engineer, Francis Collomp, in northern Katsina state in 2012. He escaped later escaped.
Ansaru claimed the December 26, 2012 attack on a maximum security facility in Abuja where captured Islamists were being held, killing two policemen and freeing 40 detainees.
The group said it was responsible for a 2013 attack on a convoy of Mali-bound Nigerian troops in Kogi state, killing two soldiers and seriously wounding five others.
It issued a statement condemning Nigeria's participation in the "war against the Islamic state of northern Mali".