PARIS (AP) — Two European aid groups said Monday that seven of the eight people killed by gunmen in a Niger giraffe park were aid workers working for them in the West African country.

The six French citizens and one Nigerien killed on Sunday were working for Paris-based NGO ACTED and Geneva-based IMPACT Initiatives, they said in a joint statement on Monday. The other victim was their Nigerien guide,

They condemned “in the strongest terms the senseless and barbaric killing of our colleagues and their guide.”

Niger’s interior ministry said Sunday the attack took place in Koure, where the aid workers were visiting a giraffe reserve. Hundreds of people visit each year the protected national park that contains dense vegetation and tall trees about 70 kilometers (45 miles) southeast of the capital.

“Our colleagues have been working to support the people of Niger facing hardship, driven by values of humanity and solidarity,” the NGOs said. They did not elaborate.

One of the biggest French NGOs, ACTED has been present in Niger since 2010 and provides aid to displaced people and local populations who are particularly vulnerable due to conflicts in the region, lack of food and droughts.

A partner to ACTED, IMPACT Initiatives was first deployed in Niger in 2012. It conducts mapping programs and other initiatives in camps hosting displaced populations.

In a phone call on Sunday, French President Emmanuel Macron and Niger President Mahamadou Issoufou on Sunday evening pledged to clarify the circumstances of the deadly attack by “all means,” the French presidency said.

The French government has warned citizens against traveling outside of the capital, Niamey, as militants linked to Boko Haram, Islamic State and al-Qaida still carry out attacks across the vast West African nation. Niger borders several countries including Mali, Burkina Faso, Chad, Nigeria and Libya.

Violence by groups linked to IS and al-Qaida is on the rise in the Sahel region. France has deployed 5,100 soldiers to help fight the growing insurgency there, and a local Sahel force made up of soldiers from Mali, Niger, Burkina Faso, Chad and Mauritania has also been fighting the extremists.