This is how the US secretly collects info on terrorists in Africa
From its base in Djibouti the USAF uses various types of aircraft to collect information on terrorist groups in Africa.
These aicraft fly Intelligence, Surveillance and Reconnaissance (ISR) missions from CAMP LEMONNIER, Djibouti for the African Union Mission in Somalia (AMISOM). The base supports approximately 4,000 U.S., joint and allied forces military and civilian personnel and U.S. Department of Defense contractors. Additionally, the base provides employment for approximately 1,000 local and third country nation workers. Camp Lemonnier is located at the Djibouti-Ambouli International Airport.
This Google maps satellite photo and Goggle Earth images shows a couple of KC135 tankers, Chinook helicopters,Bell Boeing V-22 Osprey, US Navy Boeing P-8 Poseidon, US Navy Orions and USAF C130 Hercules aircraft using the airport.
The norteasterly part has the French airbase which has some transport aircraft.

The intelligence gathering aircraft are far more interesting than these supporting aircraft. Based on twitter reports various aircraft are stationed here for a couple of weeks to months.
Some examples are N81487 a Beechcraft B300 owned by Sierra Nevada Corp but seen lately in a grey US Army livery. Likely former registration 13-00282. In June 2021 the aircraft flew almost daily missions from Djibouti towards Somalia using MAMBA01 callsign.
Seen for the first time at June 20 is Challlenger 604 N100XV (mode-s A006D5) flying an ISR-mission from Djibouti. The aircraft is registered on a company named ‘TVPX AIRCRAFT SOLUTIONS INC TRUSTEE’. This is is trustee which means aircraft owners which want to hide they own aircraft use TVPX Aircraft Solutions as the ‘owner’ of the aircraft.
Little is known about this aircraft. It flew as HZ-MEJ1 till October 2019 when it was registered to N100XV. It then received a radar bulb under the belly. The aircraft is not flying frequently. In November 2019 and October 2020 it flew a couple of local missions from Guatemaly City airport. Probably related to detecting drugs smuggling activities.
It might be based at Kissimmee Gateway Airport, near Orlando Florida.
On June 15, 2021 it departed Space Coast Regional Airport (near Orl;ando) to The Francis Stanley Gebreski airport near New York. It then flew the Lajes, Malta (fuel stop at June 17) to Djibouti.
It flew from Djibouti to Berbara port in Somalia and back to Djibouti. Berbara Port is part of Somaliland, an unrecognised breakaway region of Somalia. In 2016, Somaliland signed a 30-year contract with United Arab Emirates-owned DP World, the world’s third-largest port operator, to manage and expand the port at Berbera. The joint-venture Berbera deal is between Somaliland (30%), DP World (51%) and Ethiopia (19%). This interesting article describes the government of Somaliland does its best to keep the terrorists of Al-Shabaab out of the region.
United States Special Operations Command (USSOCOM or SOCOM) operate out of Camp Lemonnier as well. Two Dornier C-146A Wolfhoud (97-3093 & 97-3091) were seen here in May 2021.
Also a couple of Dash8-200s operated out of Camp Lemonnier for ISR missions. The registrations are not known.
A civil registered aircraft is Dash 8 N480AV operated by Berry Aviation. It often uses callsign RIPIT01 for missions towards Somali and Kenya. It has been stationed at Djibouti for months. Its mission is not clear but likely the aircraft is used for flying people and goods in the region, as well as medevac.
Two Beechcraft C-12U Huron of the US Army were seen in June 2021 operating out of Camp Lemonnier. These were 84-00153 (PAT75) and 84-00171 (PAT99). Both seem due to the absense of strange antennas and bulbs normal aircraft used for transportation purposes.
Also Pilatus U-28A Draco (like 04-0688) were seen operating out of this base using RCH1021 callsign. The mission of the Draco is to provide manned fixed-wing tactical airborne ISR support to humanitarian operations, search and rescue, conventional and special operations missions. Draco is the Latin term for dragon. The aircraft has four people on board; two pilots, 1 combat systems officer and 1 tactical systems officer.
Many of these aircraft use Souda Bay airbase on the Greek island of Creta for a fuel stop on their way from the US to Africa and back. Other airfields used are Lajes at the Azores and Rota in Spain.