Six French tourists and their local guide and driver were killed Sunday by gunmen riding motorcycles in an area of southwestern Niger that is home to the last West African giraffes, officials said.
It is believed to be the first such attack on tourists in the area, a popular attraction in the former French colony thanks to its unique population of West African or Niger giraffes.
"There are eight dead: two Nigeriens including a guide and a driver, while the other six are French," the governor of the Tillaberi region told AFP.
"We are managing the situation, we will give more information later," Tidjani Ibrahim Katiella said, without indicating who was behind the attack.
A source close to the environmental services said the assault took place at around 11:30 am (1030 GMT) six kilometres (four miles) east of the town of Koure, which is an hour's drive from the capital Niamey.
"Most of the victims were shot… We found a magazine emptied of its cartridges at the scene," the source told AFP.
"We do not know the identity of the attackers but they came on motorcycles through the bush and waited for the arrival of the tourists."
The source added that the tourists' vehicle belonged to the French humanitarian organisation ACTED.
Grisly pictures seen by AFP of the scene showed bodies lying near a torched off-road vehicle, which had bullet holes in its rear window.
Around 20 years ago, a small herd of West African giraffes, a subspecies distinguished by its lighter colour, found a safe haven from poachers and predators in the Koure area.
Today they number in their hundreds and are a key tourist attraction, enjoying the protection of local people and conservation groups.
However the Tillaberi region is in a hugely unstable location, near the borders of Mali and Burkina Faso.
The region has become a hideout for Sahel jihadist groups such as the Islamic State in the Greater Sahara (ISGS).
The use of motorcycles has been totally banned since January in an attempt to curb the movements of such jihadists.