Dougui — Nafisa Isa lost her home when a dam broke and flooded her village. Now she and her children live in a camp, threatened by malnutrition and malaria. But Nafisa doesn't want a hospital - she wants a mosque.

"Only God can save us, so we have to pray. We need a place to pray," said the 38-year-old mother of two.

Medicine has run out at the nearest clinic, a day's walk away. Treatments distributed by U.N. child agency UNICEF near the camp have been seized by unscrupulous government officials who then sell them to desperate mothers, Nafisa said.

Her plight highlights the broader one in semi-arid Far North region, home to 4 million people - a fifth of Cameroon's population.

Poverty worsened by a decade of droughts and conflicts in the Sahel belt south of the Sahara risks pushing a desperate population towards radicalism.

Many say neglect by the government in Yaounde, 700 km (400 miles) away in the largely Christian south, has left the predominantly Muslim Far North with the country's worst development indicators.

"It's a pattern we're seeing all over the Sahel. Many people don't want hospitals, or schools; they want mosques and madrassas," said Nicolas Leguen, Emergency Response Coordinator for the European Union's Humanitarian Aid arm (ECHO).

"It means they have more faith in God than in the state, and this feeling is intensified in times of disaster."

ISLAMIST UNREST

Nigerian Islamist sect Boko Haram, fighting a guerrilla war in northern Nigeria to impose Islamic law that has killed thousands, uses Cameroon's neighbouring Far North region as a base and its activities often spill across the border.

In February, seven French tourists were kidnapped by the group in Far North but later released. A French priest was seized this month by suspected Nigerian gunmen in the region.

The seizure of northern Mali by al Qaeda-linked groups last year drew international attention to how Islamists and criminal gangs can fill a gap left by weak governments in the region. France sent troops in January to destroy the Islamist enclave.

"The region of the Chad basin with Niger, Cameroon and Nigeria, is severely underdeveloped," said Elizabeth Donnelly, assistant head of the Africa Programme at Chatham House, a London-based think tank.

"You can look at politics, poverty, corruption, security and lack of justice and see how that might ferment into a sense of being disenfranchised. The risk in all ungoverned spaces is what's going to fill that vacuum."

Reclusive President Paul Biya, 80, from southern Cameroon, has clung to office since 1982. While much of Cameroon became dysfunctional under his rule, the north has suffered most.

ETHNIC DIFFERENCES

"Access to good health care and education is directly proportional to access to power," said Leguen. "As the gap grows between north and south (Cameroon), eventually something will have to give, as it has done in northern Nigeria."

Religion may not be as important a factor as ethnicity.

"There is a clear polarisation of the north and the south in terms of development but tensions are more likely to arise because of ethnic differences rather than religious ones," said a political analyst from Africa Practice, noting divisions between the northern Peul and southern populations.

UNICEF Cameroon's Souleymane Kanon said schools and hospitals in the Far North were scarce and of poor quality. Malnutrition afflicts 18 percent of northern households, compared to a national average of under 10 percent, according to a 2011 health survey. Only 30 percent of children are immunised, versus a national average of 52.1 percent.

"We have health facilities but we lack medicine, equipment and personnel," said Dr. Dama Kadjou, one of only a handful of doctors in the region. "Doctors often go to the capital for better training, a better life and a higher salary."

Experts say the very high child marriage rate among Muslim girls in the Far North means lower school attendance and increased maternal and child mortality rates.

"In terms of the Millennium Development Goals, the Far North is really far behind," said Kanon.

 - Editing by Daniel Flynn and David Lewis