At least five police officers were killed in Burkina Faso on Sunday in an attack near the border with Mali, security forces said.

It was the fourth deadly assault in a week against security forces battling jihadists in the poor West African country.

Burkina Faso has been hit by deadly jihadist attacks since 2015, mostly in the northern and eastern regions close to Mali and Niger but also in the south.

“Early this morning, around 6 am, unidentified armed individuals attacked the police station in Di,” a town located in Sourou province, a security source told AFP. “Unfortunately, five policemen were killed,” the source said, without attributing the attack to any particular group.

Another source who refused to be named, close to the security ministry, confirmed the attack and the toll. “In addition to the five fallen policemen, three others are missing,” the source said, adding that “operations are under way to find the missing policemen.”

On Friday, rebels attacked two mining convoys, killing at least one soldier and wounding another in the north and east of the country.

On Thursday, two police officers were killed in an attack in the north.

And on Monday, three soldiers were killed and seven were injured in the southwest near the border with Ivory Coast.

Attacks in Burkina Faso, often blamed on jihadist groups affiliated with the Islamic State or Al-Qaeda, have killed around 2,000 people and forced more than 1.4 million to flee their homes.