It has left Niamey, a city of nearly two million, struggling to obtain crucial wood supplies from the country's southwestern region, close to Burkina Faso where the jihadists have banned the trade in timber.

Ninety percent of households in the city use wood for cooking or lighting, according to the department of water and forestry.

Wood is used for making daily meals but also for wedding and baptism feasts. On the Muslim holiday of Eid al-Adha, more than 54,000 tons of wood, or around a quarter of the city's annual consumption, are typically used for grilling hundreds of thousands of sacrificial sheep.

The last remaining forests in the largely desert Sahel country are less than 100 kilometres (62.5 miles) from Niamey. But to reach them, the army said people faced "persistent terrorist threats", in particular improvised explosive devices on the roads.

Niger is one of several countries in Africa's Sahel region where the army has seized power in recent years in the face of persistent attacks by jihadists and other armed groups.

The border area between Niger, Mali and Burkina Faso has long been a hideout for jihadists linked to the Islamic State group and Al-Qaeda, who have waged a bloody insurgent war against the government.

"Timber traders are in disarray and total desolation, as 90 percent of their supply areas are seized by insecurity," Mamane Seydou, secretary general of the National Association of Timber Harvesters of Niger (ANEB), told AFP.

- 'Terrorist hideouts' -

Local sources said the jihadists previously regulated logging through the collection of taxes but had now banned it altogether in areas where they have influence.

"These areas are terrorist hideouts... they say we are destroying their refuges... they have warned us many times," Seydou said.

"From 2015 until now, the terrorists have killed 24 of our drivers and their apprentices and burned 52 trucks," he added.

Truck driver Hassane Gourouza said the job had become highly dangerous.

"We are risking our lives, so we have stopped going to these dangerous places," he said.

The forests bordering Burkina Faso were "a traditional pullback area for bandit groups" but have now become one for "jihadist groups", the Laboratory for Studies and Research on Social Dynamics and Local Development (LASDEL) said.

The armed groups see logging as a factor that "reduces" and "exposes" the areas to which they can retreat and make a base, the NGO said.

To subvert the process, they "threaten, kidnap and beat" those who cut wood and "burn trucks", the LASDEL said.

"Trucks and (wood) carters can no longer go into the bush" and "most of the timber markets" have closed, a former elected official in the southwest lamented.

To avoid a total shortage, trucks head to semi-desert areas northwest of Niamey, which have all experienced jihadist violence but are currently relatively calm.

- 'Ecological disaster' -

Loggers say it now takes a week in the bush to bring back a single load of wood, instead of four or five loads as was the case before the security crisis.

As a result, prices are soaring.

A wood load which previously cost 100,000 CFA francs (150 euros, $170) in the southwest has shot up to between 300,000 and 350,000 CFA francs, logger Maman Seyni said.

But even if the prices are rising, they do not make up for the impact on sales from the drop in supply.

The annual turnover for the wood industry in the capital alone, estimated at more than three billion CFA francs (around 4.6 million euros, $5.2 million), is "in free fall," according to the ANEB.

"After the surge in the price of several products, it's now wood that's expensive," grimaced Aissa, a mother of six.

Coal is the most widespread alternative.

"Gas is very complicated and expensive for us. For two years, I've been using coal," Fati Ibrahim, also a housewife, said.

The rush to sparsely forested areas also worries NGOs.

"If this large-scale logging continues, it will inevitably lead to forest depletion and ecological disaster," environmental activist Islamane Almoustapha warned.

Relaunching campaigns promoting locally produced gas and coal to curb "wild" deforestation is now a matter of urgency, he said.