The United Nations has temporarily suspended aid deliveries in conflict-ridden Borno state, in north-eastern Nigeria, after some of its workers were wounded during an attack by Boko Haram terrorists. The aid workers, along with civilians and Nigerian soldiers, were wounded as the militants ambushed a UN convoy returning from Bama town.

"The United Nations has temporarily suspended humanitarian assistance missions pending review of the security situation," the United Nations Children's Fund (Unicef) said.

Borno is the epicentre of Boko Haram's insurgency, which has caused the death of at least 20,000 people in Nigeria and neighbouring countries since 2009.

More than two million Nigerians have been internally displaced as a result of the violence with humanitarian organisations warning civilians are at risk of starvation, do not have access to proper sanitation, health services and education.

In Borno alone, almost a quarter of a million children are living in dire conditions because of the unavailability of food and medical care. As per Unicef estimates, at least 244,000 children currently displaced by the conflict were found to be suffering from acute malnutrition. Of these, almost one in five, around 49,000, would die if they failed to get medical assistance.

Nigerian army's claims on Boko Haram

Boko Haram's ambush occurred shortly after the Nigerian army declared the fight against the terrorists was successfully over. Colonel Sani Usman, spokesperson for the Nigerian army, said there were no longer Boko Haram camps in the country' s north-east, where the group targets its insurgency.

This is not the first time the Nigerian army and government have claimed that the fight against Boko Haram was over.

Nigeria is heading an ongoing regional offensive against Boko Haram. The task force consists of 8,700 troops from Nigeria, Niger, Chad, Cameroon and Benin.

The joint offensive has scored some successes, such as the recapture of several territories and the release of thousands of civilians previously held captive.

Although Nigeria's President Muhammadu Buhari declared a technical victory over the insurgents in December 2015, Boko Haram has continued to carry out attacks, with security experts warning underlying issues such as disenfranchisement, poverty and strong links with Islamic State (Isis/Daesh) continue to pose major threats to stability in the region.

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Who are Nigeria's Boko Haram terrorists?

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.