This Sunday's image shows the wreckage of the car where six French aid workers, their local guide and the driver were killed by unidentified gunmen in Niger. Photo: AFP

France pledged Tuesday to ramp up security for its nationals in the Sahel region following an attack in Niger over the weekend in which eight people, six of them French, were murdered by jihadists. 

"I've decided to boost security measures for our expatriates in the region," French President Emmanuel Macron tweeted after a cabinet meeting on what he described as "manifestly a terrorist attack."

Macron did not elaborate on the exact nature of the measures envisaged. 

Seven of the victims worked for the French humanitarian NGO, Acted. They were attacked Sunday in Koure National Park, 60 kilometers from the Nigerien capital of Niamey. 

The killings were the first by jihadist gunmen in that area, a destination for weekend leisure trips by Niamey residents, including foreigners.

French Prime Minister Jean Castex described the killings as an "odious crime" and an act of "cowardice that is difficult to put into words." 

No group has claimed responsibility for the attack but the region around Niamey has become a hideout for jihadist groups including the Islamic State in the Greater Sahara (ISGS), which has killed hundreds of troops and driven thousands of people from their homes. 

Macron vowed there would be consequences, including military ones, from the attack. 

The French military has a 5,100-member anti-jihadist force in the Sahel, which covers five countries, including Mali, Niger and Burkina Faso. 

"We're pursuing action to eradicate the terrorist groups, with the strengthened support of our partners," Macron said. 

AFP