Two Spaniards, an Irish conservationist and a local soldier have been abducted near a nature reserve in Burkina Faso.
The group was part of an anti-poaching patrol that was ambushed by gunmen near Pama reserve on Monday.
No group has said it carried out the attack.
Burkina Faso is facing a deepening security crisis, like many of its neighbours, as Islamist armed groups carry out raids and kidnappings across much of the region.
Both Spain’s and Ireland’s foreign ministry said they were liaising with local authorities over their missing nationals.
An unnamed local official was quoted by AFP news agency as saying that three people were also wounded in the attack on the group, which was made up of soldiers, forest rangers and foreign reporters.
Gunmen in two pick-up vehicles and a dozen motorbikes ambushed them on a road leading to the vast forested reserve of Pama in Burkina Faso’s East Region, AFP reports.
The kidnappings are the latest in the former French colony where wildlife reserves used to be popular with tourists.
But many of them are in territory now exploited by jihadists.
Militant Islamist groups are believed to be holding several foreigners hostage in Burkina Faso, as well as in the neighbouring states of Mali and Niger, Reuters news agency reports.
The semi-arid region, known as the Sahel, has been hit by an insurgency since the militants captured last parts of northern Mali in 2012 and 2013.
France and other foreign troops have deployed troops to the region, but have failed to end the insurgency.
The conflict has displaced nearly three million people.