Tens of thousands of people in Nigeria are missing out on vital services because of conflict, with the areas where Boko Haram operates worst affected, the Red Cross said on Thursday.

The ICRC said it had helped some 40,000 people hit by the Islamist insurgency in the northeast, by religious and ethnic tensions in central Nigeria, and by crime in the oil-rich southern Delta region.

Niger on Wednesday called for Western intervention to eradicate a growing threat from Islamist fighters who have established bases in southern Libya since the 2011 overthrow of Moamar Gadhafi.

"The powers who intervened to overthrow Colonel Gadhafi -- after which Libya became the main sanctuary for terrorists -- need to provide an after-sales service," Niger's Interior Minister Massoudou Hassoumi told Radio France International.

The U.S. military's partnership with France in Africa is "indispensable" in the fight against extremist groups in the Sahel region, French Defense Minister Jean-Yves Le Drian said on Friday.

During a visit to Washington, Le Drian said "terrorist groups are circulating across the whole Sahara-Sahel area and terrorist acts could put our own security at risk."

Thousands of opposition supporters took to the streets of the Niger capital Niamey on Saturday to protest corruption and media censorship, in the first major rally against President Mahamadou Issoufou's rule since his 2011 election win.

Demonstrators chanted "Down with the regime!" and "No to dictatorship" as they gathered outside parliament, with some carrying portraits of ex-president Mamadou Tandja, who was ousted in a military coup in 2010 but remains a popular figure in the west African country.

Niger police arrested a man on suspicion of planning two terror attacks against strategic sites in the capital Niamey, the justice minister told Agence France Presse on Thursday.

"If these attacks had been carried out it would have been dramatic," the minister said, adding that security had been reinforced around the areas that had been targeted.

More than 37,000 people have fled violence between the army and Boko Haram insurgents in northern Nigeria for neighboring Niger, the United Nations said Wednesday.

According to the latest report from the U.N. Office for Humanitarian Affairs (OCHA), "37,332 people fleeing clashes in the states of Borno, Yobe and Adamaoua in the north of Nigeria (...) have been registered in Diffa, southeast Niger".

The Niger authorities on Monday rescued 72 illegal migrants stranded in the scorching Sahara desert after their truck got a flat tyre.

The people who found them were on their way to the burial site for some of the 92 migrants who died of thirst after a similar incident last month.

Niger has rounded up close to 150 migrants crossing the Sahara to Algeria in the past two days, in a crackdown on illegal migration after 92 people died of thirst trying to make the same desert journey.

The grisly discovery Wednesday of the bodies of mostly women and children left stranded in the harsh Sahara desert after their trucks broke down, has prompted Niamey to clamp down on migrant trafficking networks.

The bodies of 87 migrants were found Wednesday in Niger's desert north after they died of thirst, a security sources said.

The corpses of the seven men, 32 women and 48 children were in addition to five bodies of women and girls found earlier, the sources said, adding that they had been trying to emigrate to Algeria.

Four Frenchmen held captive for three years by an al-Qaida offshoot in North Africa flew home to their families on Wednesday, as sources said at least 20 million euros had been paid in ransom.

The four men, who were kidnapped by al-Qaida in the Islamic Maghreb (AQIM) in northern Niger in 2010, flew into the Villacoublay military airport near Paris, where they were met by their families and President Francois Hollande.