The aftermath of an attack in Niger's Koure that killed six French aid workers, sparking Paris to issue a strong travel warning. [AFP]

"I am furious at France," Mahamane Rabiou Bachir said over the blaring sounds of traffic in Niger's capital, Niamey.

He is far from alone in Niger, where anger is still seething nearly a week after the former colonial ruler issued a stern warning against travel to the West African country.

France classified all of Niger except the capital as red under its colour-coded security advice after six young French aid workers were among eight killed in a suspected jihadist raid on August 9.

The attack at the Koure National Park, a giraffe haven and tourist hotspot outside the capital, was the first of its kind against Westerners in the area and prompted an outpouring of grief in France.

Koure had previously been marked as yellow, but on Wednesday France put everywhere in the most severe "red zone" except Niamey, which is orange (travel "not advised unless for compelling reasons").

The fear of reputational damage has not gone down well in Niger, whose economy was already reeling from jihadist insurgencies in the west and southeast.

Some have been quick to portray the move as a slap by a former ruler which prefers to see Niger in terms of a logistics point for its anti-jihadist campaign.

"If France goes so far as to classify Niger as a red zone, then it's very simple: they close their embassy and their military base," Bachir said.

'Truly villainous'

"Any Nigerien concerned about the dignity of this country feels humiliated in their bones. Niger in red! But they have only have to leave, for goodness' sake, they just have to leave," said Alahe Tahirou, a civil servant. 

Lawyer and academic at the University of Niamey, Amadou Hassane Boubacar, called France's decision "punitive" and "truly villainous".

"I urge Niger's government to protest... it is totally arbitrary and ultimately shows contempt for the people of Niger."

Outrage has also reverberated across social media, where many have shared a completely green map of Niger with the words: "I am a country of legendary peace and hospitality, I am Niger."

Niger's state TV station Tele Sahel judged that Paris made an emotional decision under the influence of "panic". 

"It is an unjust decision which discourages all the efforts over the last five years by the authorities and the defence and security forces to preserve the integrity of this territory surrounded by numerous tension hotspots".

The CGSL trade union group slammed France's "hasty, provocative and disrespectful attitude".

But others said they understood the reason for the French move.

"It is also our fault," said Bello Alou, a young mechanic. "There is not enough security, there are too many bandits in the country."

Economy fears

Niger is among the world's poorest countries, for nine straight years ranking dead last out of 189 nations in the UN's Human Development Index.

Local businessman Ali Maman warned that the travel warning "risks sowing panic among investors when the economy is already being affected by the coronavirus".

According to the French economy ministry, annual investment in Niger by French companies rose steadily from 2014, reaching around a billion euros ($1.19 billion), led by transport infrastructure and uranium mining, in 2017.

The country was the ninth biggest destination that year for French funds south of the Sahara.

No one has yet claimed responsibility for the Koure attack, but a source close to an ongoing investigation by French anti-terror prosecutors told AFP that it appeared to have been planned and targeted at "mainly Westerners".

France has previously been sensitive to harsh words from its former colonies in the Sahel, where French Barkhane troops are among those fighting a rising jihadist insurgency across the region.

There are also concerns the French travel warning could affect Niger's high-stakes presidential election on December 27.

President Mahamadou Issoufou will not run for re-election after serving two terms, and the ruling party has nominated powerful former interior minister Mohamed Bazoum as its candidate.

Ibrahim Yacouba, a former foreign minister turned opposition presidential candidate, warned that if the "red zone persists" it could "prevent credible international observers from being there".