The Democratic Republic of Congo's army says it has killed a rebel leader in the country's troubled northeast.

The army made the announcement on Saturday, just hours after 13 people were killed in the region.

It said soldiers shot dead Mouhamed Mukubwa Islam – one of the top three leaders of the Allied Democratic Forces (ADF) group – during a military operation late on Friday in Mapobu forest, in the Beni region of North Kivu province. The ADF militia group is originally from Uganda.

Militia violence in the DR Congo's northeast region has spiked in recent months, killing scores of people and forcing thousands to flee their homes.

The DR Congo army is carrying out an operation in the country's northeastern region to root out militant groups including the ADF.

"The killing of this leader is another sign that we have the capacity to end this rebellion in the coming days," Al Jazeera quotes General Leon Richard Kasonga.

"It will not be an easy task as the enemy is trying to turn the [local] population and opinions against the army by killing people in the city," he added.

The killing of Islam is the second of a high-profile rebel leader since the army's operation which began last month.

Earlier this month, Congolese forces killed Nasser Abdullayi Kikuku, another senior leader of the group that has also been blamed for the recent upsurge of violence in the area.

(With input from Al Jazeera)