Three European journalists -- two Spanish and one Irish -- have been killed in an attack on an anti-poaching patrol in Burkina Faso, officials said Tuesday. 

"Three foreign nationals have been killed and a Burkinabe is missing," government spokesman and communications minister Ousseni Tamboura said in a statement, adding that six people had been injured in the attack in the eastern region of Fada N'Gourma-Pama. 

A senior security source in the West African country said the three foreigners -- all identified as journalists by the rights group Reporters Without Borders -- had been "executed by terrorists".

He did not specify who was behind Monday's attack targeting the group, which had included soldiers and forest rangers as well as foreign reporters.

The attackers used two pick-up vehicles and a dozen motorbikes, according to security sources.

See Also: Saudi Crown Prince strikes conciliatory tone with rival Iran

Spanish Prime Minister Pedro Sanchez confirmed that two Spanish journalists had been killed. 

"The worst news is confirmed. All our affection for the relatives and friends of David Beriain and Roberto Fraile (de Baracaldo), who were murdered in Burkina Faso," he tweeted. 

He praised "those who, like them, carry out courageous and essential journalism from conflict zones".

Spanish Foreign Minister Arancha Gonzalez Laya told a news conference that the two men were "making a documentary on the measures taken by Burkina Faso to protect national parks, to protect natural resources from poaching and to protect the populations living in the natural parks."

- Seasoned reporters -

She said Beriain was from Pamplona in Spain's north while Fraile was from the northern Basque country.

Beriain was a war reporter who worked for a now defunct Spanish branch of CNN and had founded his own production house specialising in documentaries on illegal activities.

Fraile used to work for Spain's CyLTV. According to Spanish media reports, he was wounded in Syria at the end of 2012 while covering the Free Syrian Army.

Both were described as seasoned war journalists.

Adriano Moran from Beriain's production house 93Metros said they had only been in Burkina Faso for a short while.

"Both of them knew that it was difficult terrain and that such a thing may happen. And the worst happened," he told Spain's TVE.

"David was one of the great journalists of the country and the world," he said. "He had received many prizes."

Moran said Beriain had a satellite phone with him but had been incommunicado for the past few days.

Ireland's foreign ministry did not provide details, simply saying it "has been in contact with the family of the Irish citizen and is providing all possible consular support."

The European Union's foreign policy chief Josep Borrell said the "terrorists have once again showed their cowardice and criminal face: the defenders of an obscurantism which annihilates all freedom of expression and speech."

- 'Great dangers' -

Underscoring the country's fragile security situation, gunmen killed at least 15 people in an overnight raid on several villages in the northern Seytenga area, a local lawmaker said on condition of anonymity, with at least five more kidnapped.

One of the poorest countries in the world, Burkina Faso is struggling with a ruthless insurgency by armed Islamists who swept in from neighbouring Mali in 2015.

Jihadist groups -- some affiliated to Al-Qaeda and others to the Islamic State group -- have launched increasing numbers of attacks in the country. 

Almost 1,100 people have died and more than a million people have fled their homes.

The secretary general of Reporters Without Borders, Christophe Deloire, decried the attack.

"This tragedy confirms the great dangers reporters face in the Sahel region," he said on Twitter.

Monday's killing was not the first targeted attack in the country. 

A kidnapped priest was found dead in a forest in January, days after he went missing in the jihadist-plagued southwest.

And last August, the grand imam of the northern town of Djibo was found dead three days after gunmen stopped the car he was travelling in and kidnapped him.

In March 2019, a priest in Djibo was kidnapped, and in February 2018, a Catholic missionary, Cesar Fernandez, was murdered in the centre of the country.