DAKAR (Thomson Reuters Foundation) – People uprooted by Boko Haram violence in northeast Nigeria are leaving host families and moving to camps for the displaced as food becomes increasingly scarce, the European Commission’s humanitarian arm (ECHO) said on Wednesday.

Seven million people in that part of the country do not have enough to eat and almost one-third of them need urgent food aid, according to the U.N. Office for the Coordination of Humanitarian Affairs (OCHA).

Nine in 10 of Nigeria’s 2.2 million internally displaced people are living with host families in the northeast rather than in camps, amid food shortages that are raising tension in many households, said Thomas Dehermann-Roy, head of ECHO’s Central Africa office.

“It is easier to host your neighbours, friends and family when everything is fine, but when food becomes scarce – tensions are raised,” he said.

Around two-thirds of people uprooted by conflict and four in five host families in northeast Nigeria said food was their most pressing and unfulfilled need, according to ECHO.

“Some people are moving to camps as the living situation with host families becomes too harsh – it is a worrying trend and sign of a deteriorating situation,” Dehermann-Roy added.

A regional offensive by Nigeria, Niger, Chad and Cameroon last year drove the militant group Boko Haram from much of the territory it held in northern Nigeria, undermining its six-year campaign to carve out an Islamist caliphate.

But the militants have since struck back with suicide bombings and hit and run attacks on civilians, threatening livelihoods and hindering aid agencies’ efforts to deliver food.

The amount of land being used to grow food has dropped by almost 70 percent over the past year as the violence has disrupted farming and driven people off their land, OCHA said.

A Nigerian government push to stop Boko Haram from raising funds by selling livestock has shut down the cattle trade in Maiduguri, while the conflict has stifled cross-border trade with neighbouring Cameroon, Chad and Niger.

The government is encouraging the displaced to return home, but the continuing arrival of newly uprooted people in Maiduguri – the capital of worst-hit Borno state – suggests that parts of the northeast are still unsafe, according to ECHO.

“There is a concern that aid agencies may not be able to reach or provide assistance to people who go back to insecure areas,” said Dehermann-Roy.

A lack of food could drive people to desperate measures including selling their possessions and trading sex for food, he added.

(Reporting By Kieran Guilbert, editing by Tim Pearce)