Bloodthirsty Abubakar Shekau is one of the world’s most wanted men, with American authorities putting a $7million bounty on his head.

Shekau – said to be to fluent in four languages – also operates under a variety of different names which has only increased the mystery surrounding his true identity.

The elusive Islamist fanatic has led his brutal Boko Haram militants since 2009 into war in Africa, killing more than an estimated 16,225 people in that time.

The latest outrage he has led was the massacre of an estimated 2,500 people in northern Nigeria when his thugs razed two towns.

Last week, the terror group shocked the world when they are believed to have used girls as young as 10 as suicide bombers in two deadly attacks in northern Nigeria that killed at least 19 people.

Experts claim psychotic Shekau rarely communicates directly with members of the terror group and instead deals only with a handful of confidantes - much like former Al Qaeda terror chief Osama bin Laden.

Files on the US State Department of Justice claim he variously operates under identities that include Darul Tawheed, Abu Bakr Skikwa, Imam Abu Bakr Shiku, Abu Muhammad Abu Bakr Bin Muhammad Al Shakwi Al Muslimi Bishku and Abubakar Shakkau. 

The four languages he speaks are listed as Arabic, Hausa, Fulani and Kanuri. Even his age remains unknown, with predictions between 38 and 49 believed to be most accurate.

Shekau is believed to have a wife and three children, although their whereabouts also remain unknown. 

The Nigerian military has claimed several times to have killed the fanatic - only for him to appear in new videos proving he is still alive.

After one recent claim, he appeared in video to taunt the military's claims and laughed: 'Here I am, alive. I will only die the day Allah takes my breath.'  

Boko Haram – which means ‘Western education is forbidden' in Arabic – have shocked the world with their merciless slaughter of innocent men, woman and children across the north of Nigeria.

Shekau claimed leadership of the terror group in 2010, and was seen last week in a video praising the jihadists who murdered 17 people in the Paris attacks.

He has been variously described as ‘fearless’, a ‘gangster’ and a ‘loner’, which security sources believe give him an air of invincibility which makes him extremely dangerous.

The Terrorism Research and Analysis Consortium has described Shekau as a ‘religious intellectual, yet also a gangster and vigilante as well as a mad leader’. 

Under Shekau’s leadership, Boko Haram has continually targeted young children. In April 2014, Boko Haram kidnapped close to 300 girls from their school in Chibok in Borno State in northern Nigeria.

In a video message released three weeks later, Shekau claimed responsibility for the kidnappings, calling the girls slaves and threatening to sell them. 

He boasted: 'I abducted your girls. There is a market for selling humans. Allah says I should sell. He commands me to sell.'

Their disappearance prompted a social media campaign with #bringbackourgirls, which was supported by Michelle Obama, First Lady of the USA.

(dailymail.co.uk)