The leader of the Islamic State militant group that controls parts of Syria and Iraq has accepted a pledge of allegiance from the Boko Haram sect.
The spokesman to the Islamic State leader, Abu Mohammad al-Adnani, purportedly said this in an audio message transmitted on Thursday.
This comes six days after the leader of the Boko Haram sect pledged formal allegiance to the Islamic State (ISIS) in an audio recording released on Twitter.
Boko Haram is not the first extremist group to pledge allegiance to the self-proclaimed caliphate in Iraq and Syria. Others in Afghanistan and Pakistan have already done so.
Boko Haram began a campaign to impose Islamic rule in northern Nigeria in 2009.
The insurgents have been responsible for several bombings, mass kidnappings, attacks on churches and mosques and attacks on villages leading to several deaths of civilians and soldiers of the Nigerian Army.
However, the pledge and acceptance of alliances notwithstanding, the Nigerian military says that it would continue to enhance the effectiveness of its mission to curtail the terrorists.
The military says the fighting patrols by air and land are being stepped up in the forests and hills of the affected areas and other parts of the north east where the Boko Haram terrorists are hiding.
The Nigeria Army has also vowed that the security forces would continue to employ necessary fire power to protect its territories.