Authorities in Niger, who have sent troops to help battle Islamists in neighbouring Mali, are wary of armed extremists filtering across the desert border and of an uprising by the domestic Tuareg population.
Since French troops deployed in Mali on January 11 to tackle the armed Islamists, Niger's government has ordered round-the-clock military patrols in the capital Niamey and stepped up security around hotels and foreign embassies.
"Never seen anything like it, except during coups d'etat," said a resident in the plush Plateau residential district, home to many expatriates.
It was there that Al-Qaeda in the Islamic Maghreb (AQIM) in January 2011 took two young French hostages, who subsequently died during a failed rescue bid by the French military.
The abduction in the capital was among the most spectacular operations carried out by Islamists in Niger in recent years, together with the kidnapping of seven expatriate workers at the uranium mine run by French nuclear group Areva at Arlit in the north in September 2010. AQIM still holds four French hostages.
"The threats that exist in Mali constitute a domestic security problem for Niger," President Mahamadou Issoufou recently said.
A long-standing proponent of using force against AQIM and its allies, who seized control of northern Mali last year, Issoufou sent a battalion of 500 Niger soldiers to join the West African peacekeeping force deployed there.
These soldiers, considered well-trained and tough, are presently the most committed African troops in Mali, along with a Chadian contingent that is battle-hardened in desert warfare.
At home, Niger's rulers have adopted preventive tactics. The government says it is doing its best to patrol the 800-kilometre (500-mile) border with Mali to deter any infiltration.
The speaker of the National Assembly, Hama Amadou, warned "terrorist" forces could "deploy in the direction of Niger" after armed Islamists took dozens of hostages in January at a gas site in Algeria's southeastern desert to avenge French military action in Mali.
At least 37 foreigners and one Algerian hostage were killed when Algerian special forces stormed the complex, along with 29 hostage-takers.
-- "Impossible to control everything" --
The attack led France to send special forces to protect the Areva sites in Niger, which are the poor and largely desert nation's main source of foreign income.
But "in spite of all the best intentions of the security forces, it is impossible to control everything," an official close to Niger's ruling elite said.
The Niamey government has welcomed US plans to deploy reconnaissance drones in Niger to monitor AQIM activities in the vast Sahel region.
Officials are also closely watching the role played by Tuaregs in the National Movement for the Liberation of Azawad (MNLA), whose fighters captured northern Mali before AQIM and its allies sidelined the Tuaregs.
Like Mali, Niger has been prone to Tuareg separatist uprisings, but both countries' governments made several peace deals with the traditional nomadic tribes. Mali considers the MNLA as the only force it would be prepared to negotiate with among the armed movements in the north.
However, Niger's President Issoufou has made forceful demands for the disarmament of the MNLA and spoken out against talks with the movement on self-determination, a stance that surprised some observers.
"If the demands of this Tuareg armed group are met (in Mali), there will be a big temptation for their Tuareg brothers in Niger, who for the moment are content with decentralised rule of their territory. The north of Niger is certainly going through a calm period, but everything could change very fast," an African diplomat posted to Niamey said.
Niger's Tuareg community -- about nine per cent of the country's 15 million inhabitants -- will not "dig up the battle-axe", countered a former rebel leader in the town of Agadez, in the heart of Tuareg territory.
Many leaders of past Tuareg uprisings -- the last dates from 2007-2009 -- have been integrated into public service in Niamey or become elected officials in the north. In a symbolic move, Issoufou made a Tuareg, Brigi Rafini, his prime minister on taking power in 2011.
In Mali, "they have to solve the MNLA problem through dialogue," said the former rebel leader in Agadez. "Otherwise, the tension will never ease in the north of Mali and throughout the Sahel."