Three United Nations agencies are raising the alarm that drought, conflict and high food prices will drive millions of people in West Africa's Sahel region into malnutrition and further insecurity without immediate aid.

Analysts say this could be one of the worst crop seasons in several years and many families may exhaust their food reserves early. That's according to the World Food Program, the U.N. children's agency and the Food and Agriculture Organization.

Insecurity in the Sahel has forced tens of thousands of people to leave their homes and has led to the closure of schools and disruption of basic social services.

The agencies warn that such vulnerabilities create an environment where extremism can thrive.

Fighters affiliated with the Islamic State group and al-Qaida already are active in the region.