The UN mission in Democratic Republic of Congo has started to deploy unarmed surveillance drones to monitor rebel activity near the forested borders with Rwanda and Uganda.
This is the first time any UN mission has deployed drones.
The first two were launched from the eastern city of Goma, which was last year briefly occupied by M23 rebels.
The UN force in DR Congo played a key role last month in defeating the M23 but other militias still operate.
The BBC's Maud Jullien in eastern DR Congo says it has long been suspected that various armed groups in the North Kivu province get their supplies from neighbouring countries.