Three suspected jihadists were killed and one was captured Tuesday in a pre-dawn raid by security forces on a house in Ouagadougou, the capital of Burkina Faso, the defence ministry said.
A member of the special gendarmerie unit which carried out the raid died of his wounds, and five other people - four gendarmes and a civilian - were injured, it said in a statement.
An AFP reporter saw two corpses in front of a suburban house and a third in a courtyard.
Police found six assault rifles, explosives and detonators, military clothing, mobile phones and SIM cards, and a notebook with writing in Arabic, the statement said.
Burkina Faso is in the grip of a three-year-old jihadist insurgency that has killed scores of people and driven thousands from their homes.
A police officer, speaking on condition of anonymity, said the operation lasted from 03:00 to 07:00.
Local resident Issiaka Ilboudo, who lives opposite the house on the southwestern rim of Ouagadougou, said there had been "intense gunfire".
"It was around 03:00 that we heard noise, it was people running on the roofs of the houses," Ilboudo said.
"We then heard shooting, which sometimes lasted 30 or 45 minutes, then stopped and resumed."
Another resident, Pascal Lengani, said the house had been newly built and put up for rent last July, but nobody in the neighbourhood knew the inhabitants or had any idea how many lived there.
Many attacks in the insurgency have targeted security forces and officials on the border with Mali.
Tuesday's operation came eight days after the assassination of the prefect - the state's paramount representative at local level - in Oursi, a town in the far north near the Mali frontier.
In April, the authorities in the eastern and northern border regions arrested around 100 people and seized explosives.
Ouagadougou has come under attack three times.
In January 2016, jihadists attacked the Splendid Hotel and a cafe, leaving 30 dead, around half of them foreign nationals.
In August 2017, two young gunmen opened fire on people at a Turkish restaurant just metres away from the Splendid Hotel, killing 19 people, at least eight of them foreigners.
On March 2 this year, jihadists attacked the country's military headquarters and the French embassy, in a coordinated operation claimed by an organisation calling itself the Group to Support Islam and Muslims (GSIM).
Eight soldiers and eight assailants were killed, and 61 soldiers and 24 civilians were injured, according to an official toll released three days later.
A government source told AFP that there were strong suspicions that "army infiltrators" had tipped off the assailants.
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