UNITED NATIONS (AP) — The Security Council has approved the use of surveillance drones over eastern Congo to monitor roving militias so it can more effectively deploy U.N. peacekeepers.

A letter released Thursday from the president of the Security Council to Secretary-General Ban Ki-moon said that the council members note the robot spy planes will be used “on a case-by-case basis” and will not set a precedent for the U.N.’s general consideration of “legal, financial and technical implications of the use of unmanned aerial systems.”