The Nigerian army has claimed it arrested 564 members of Boko Haram terror group as the offensive against the Islamist outfit continues in north-eastern Nigeria. Soldiers also freed 1,880 civilians held captive by the terrorists.

The military operation was conducted in the Sambisa forest, Borno state, believed to be Boko Haram's last stronghold.

Major General Leo Irabor said: "Five hundred and 64 Boko Haram terrorists were arrested while 19 others surrendered to our troops. Also, seven suspected kidnappers and 37 foreigners were equally arrested.

"During our operations in the period 14-21 December 2016, a total of 1,880 civilians were rescued from Boko Haram enclaves."

Irabor was speaking during a conference in Borno's capital Maiduguri, Boko Haram's birthplace.

He added several Boko Haram fighters were killed and a cache of arms and ammunitions was discovered in the operation.

The army is also believed to have started the construction of a road network to Sambisa to ease troop operations.

"We have embarked on road construction within the Sambisa forest to open up the area and also ease our operations within the theatre," Irabor explained. "Construction of the roads will ease fighting troops in their effort to mop up the Boko Haram insurgency from their hideout."

Military offensive and hunger crisis

In addition to its own military operation, Lafiya Dole, Nigeria is now leading a regional offensive – consisting of 8,700 troops from Nigeria, Niger, Chad, Cameroon and Benin – against Boko Haram.

The offensive has scored some successes, such as the recapture of key territories and the release of thousands of civilians held captive by the group.

Nigeria's President Muhammadu Buhari, who vowed his administration would defeat Boko Haram – has repeatedly called for a global effort to tackle the humanitarian crisis in the Lake Chad water basin, which comprises Chad, Cameroon, Niger, and Nigeria.

Earlier this year, the UN warned at least 400,000 children in north-eastern Nigeria alone are now at risk of starvation as a result of prolonged violence and displacement.

In December, the UN launched a $1 bn (£783m) funding appeal to help tackle what it defined as "the largest crisis on the African continent".

However, Buhari accused the UN and aid groups of exaggerating the extent of a hunger crisis in order to receive more funds.

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Who are Nigeria's Boko Haram?

Boko Haram, which has renamed itself Iswap, fights against Western influence in Nigeria and aims to impose its version of Sharia law throughout occupied territories.

The group launches attacks in Nigeria and neighbouring countries in a bid to take control of more territory. Three Nigerian states – Adamawa, Borno and Yobe − have been under a state of emergency since May 2013.

Boko Haram has killed more than 20,000 people since 2009 and was deemed the world's deadliest terror group, surpassing Islamic State in November 2015. Nigeria has also become the world's third-most terrorised country as a result of the group's violent insurgency.