Jihadist violence in Mali, Niger and Burkina Faso has forced nearly 1 million people to flee their homes, destroyed fragile agricultural economies and hobbled humanitarian aid efforts, the World Food Programme (WFP) said on Tuesday.

Groups with links to al Qaeda and Islamic State, once confined to lawless areas of northern Mali, have in recent years spread across the arid scrublands of the Sahel, to the south of the Sahara, into Burkina Faso and Niger, stoking local ethnic conflicts and attacking security forces wherever they go.

“The world does not yet fully grasp the extent of the mounting humanitarian crisis in the central Sahel region,” said WFP spokesman Herve Verhoosel. “If we do not act now to tackle hunger in the Sahel, a whole generation are at risk.”

In all, 860,000 people have been displaced across the three countries and 2.4 million are in need of urgent food assistance, the WFP said. But a lack of security stops most of the aid reaching those in need.

Despite the presence of growing ranks of international troops, the violence continues to spread.

On Monday, unidentified gunmen killed 24 Malian soldiers and wounded 29 in an ambush that bore the hallmarks of a jihadist attack. It was the third major attack against the army in less than two months that together have killed over 100 soldiers.

Those attacks mark a step-up in violence, according to records from the Armed Conflict Location and Event Data Project, an NGO. In 2019, about 95 members of the Malian security forces, including soldiers, policemen, gendarmes and other officials, were killed. So far in 2019, about 249 have died.

Peace has been shattered in Burkina Faso, wherein the first half of 2019 civilian deaths were four times what they were for the whole of 2018. One-third of the country is now in a conflict zone, the WFP said. There were 480,000 people displaced at the end of 2018, which is expected to rise to 650,000 by the end of 2019.