Two Spanish journalists and an Irish citizen have been killed after they were kidnapped during an anti-poaching patrol in Burkina Faso on Monday.

Spanish Prime Minister Pedro Sánchez confirmed the deaths of the Spanish nationals Tuesday in a post on Twitter. "The worst news has been confirmed. All of our affection for the families," he wrote.

Sánchez identified them as David Beriain and Roberto Fraile.

The pair were part of a group of 40 people patrolling a national park near the border of Burkina Faso and Benin in West Africa, Spain's Foreign Minister Arancha González Laya told a press conference in Madrid Tuesday shortly before their deaths were officially confirmed.

González Laya said the journalists - both from northern Spain - had been with an Irish citizen and described the area as "dangerous" because "terrorists and bandits" are known to operate there.

The Spanish journalists were making a documentary on Burkina Faso's efforts to protect nature preserves, including from poaching, González Laya said. She added authorities are still trying to ascertain the circumstances surrounding the deaths as the information about what really happened was "confusing."

The Irish citizen was later identified as Rory Young, the co-founder, and CEO of Chengeta Wildlife, a wildlife protection, and anti-poaching charity.

The organization confirmed his death on its social media accounts, offering its "thoughts and prayers" to the families and describing Young as an "inspirational leader."

The charity said Young had been leading the wildlife protection patrol with the journalists documenting his work when the group "was attacked by terrorists."

Burkina Faso's communications ministry said in a statement on Tuesday that the group - made up of military forces and foreigners - was attacked by armed individuals while in the Pama reserve on Monday morning.

"According to the first news available, during their journey, the team came across a position held by terrorists who opened fire," the ministry's statement said. "For the moment, the identities of the kidnappers have not been clearly established."

Beriain's production company in Madrid, 93Metros, said both men were experienced journalists, with director Adriano Morán describing his colleagues as "a hurricane of truth."

"Beriain managed to embed inside the FARC in Colombia, he showed us the real truth of Spain's role during the Iraq war and showed us an unknown look at the Taliban in Afghanistan.

Each time he came back from a trip, we all stood up and applauded, which he didn't like," Morán said. "David, with a strong style and ability to inspire trust, strength, and kindness, was able to show the most complex and unfair realities on the planet with audience's huge success."

Morán said he had not only lost a partner but "also one of my best friends." The director added that he did not know Fraile as well but described him as "an experienced reporter who already had a few close calls with death."

"He was the same type of person. Humble, educated, extremely wise and calm. An excellent person, whose humility was only comparable to his extraordinary professional capacity," Morán added.

Reporters Without Borders Spain also paid tribute to the two journalists' work in a Twitter post.

"David Beriain and Roberto Fraile were killed while they were producing one of their greatest reports about nature preservation. Despite our sadness, [we] are proud of their commitment to difficult and forgotten realities," the tweet read.