By Stijn Mitzer and Joost Oliemans
Satellite imagery from the 19th of October 2021 indicates that the S-125 surface-to-air missile (SAM) site located northeast of Mekelle has returned to active duty.  The reactivation of the SAM site comes as the Ethiopian Air Force (ETAF) has deployed its newly-acquired Wing Loong unmanned combat aerial vehicles (UCAVs) over Mekelle to designate targets for Su-27 fighter aircraft, resulting in a number of civilian casualties as the bombs dropped by the Su-27s missed their intended targets and fell on civilian areas instead.  
In one instance, a United Nations flight that was supposed to land at Mekelle was even forced to abort its landing as a result of dangerous maneuvers conducted by one Su-27 and the smoke rising from the bombs the aircraft dropped.  This particular case also highlights the danger of the presence of SAM systems in the inventories of non-state actors that logically will attempt to use them against enemy aircraft conducting bombing sorties against territory under their control. Had Tigray forces attempted to shoot down the Su-27, the missile(s) fired at the aircraft could have accidentally hit the nearby UN flight instead.
That Tigray forces are now once again in the possession of missiles that are capable of shooting down fighter aircraft or drones flying over Mekelle is a worrying trend. As the airspace over and around Tigray is still frequently used by passenger aircraft and other civilian aircraft (such as those of the UN), the threat of mistaken identity or a missile missing its intended target to hit a civilian aircraft instead is ever present. In response to the UN flight incident, a spokesperson for Tigray forces said ”our air defence units knew the UN plane was scheduled to land and it was due in large measure to their restraint it was not caught in a crossfire”. 
In July 2014 the Russian Army shot down Malaysia Airlines Flight 17 while flying over Eastern Ukraine. The operators of the Buk SAM system had mistaken the Boeing 777 airliner (carrying 298 passengers and crew) for a Ukrainian Air Force An-26 transport aircraft, killing all onboard. While the MH17 disaster highlighted the risk of continuing to fly over active warzones, little concrete measures have been taken to avoid incidents like these from happening again. Further exacerbating the situation is the fact that to many the Tigray War has remained much more obscure than the War in Donbas, making it unlikely that any serious precautions will be taken soon.
Left: Empty launch rails on the 17th of September 2021. Right: Each of the two launchers is now equipped with four missiles on the 19th of October 2021.
Footage released by Tigray forces in September showed its forces recovering several missile canisters for the S-125 SAM, perhaps serving as a first hint that it was attempting to reactivate at least one of three S-125 SAM sites it originally captured in November 2020. Around the same time, a 36D6 ‘Tin Shield’ radar was filmed driving through a village under Tigray control. These systems are the most capable radars in Ethiopia and can be linked to a S-125 site to aid in the detection and targeting of enemy aircraft.  At least two 36D6s are confirmed to have been captured by Tigray forces. 
S-125 missile containers are recovered by Tigray forces. The missiles stored in these very containers might have been used to rearm the site north of Mekelle.
When Tigray forces began their conquest of the region in November 2020, they quickly seized control of three S-125 and one S-75 SAM sites in addition to a number of radar stations.  By cobbling together enough personnel that defected to the Tigray side, its forces quickly used both the S-75 and S-125 SAM systems against their former owners.   Several follies of missiles were fired off against Ethiopian Air Force aircraft flying in the area in the weeks that followed, apparently with little success as no downings related to these launches were reported by either side. 
Interestingly, the Ethiopian Air Force made no attempt at destroying the SAM sites in return, perhaps indicating that it initially considered it unlikely that Tigray forces could or would reactivate them for future use. When Tigray forces did put them to use, the Ethiopian military still ignored the threat while at the same time flying transport aircraft over the region. Presenting easy targets even to the older S-75 and S-125 SAMs, it could be argued that only through sheer luck on the Ethiopian side no downings occurred. Tigray forces are believed to have achieved more success through the use of MANPADS, possibly shooting down as many as five ETAF aircraft and helicopters since November 2020. 
A SNR-125 fire-control radar of the S-125 SAM system in Tigray hands.
The use of surface-to-air missiles by rebel groups represents a threat that one day might result in the shoot down of a Ethiopian fighter aircraft or, god forbid, a civilian airliner. Incidents like those over Ukraine in 2014, and another massive loss of life in Iran in 2020, in which the Iranian Islamic Revolutionary Guards Corps (IRGC) mistook an airliner for a cruise missile resulting in the deaths of all 176 inhabitants, seem to naturally accompany the neglect for human life that arises in times of conflict. As civilian airliners still fly regular flights over the contested region of Tigray at the same time as the Ethiopian Air Force flies its sorties, all ingredients for such a disaster to repeat itself are present, an opportunity for tragedy to claim another freight of unwitting souls. The resulting catastrophy is sure to attract more international media attention than that of the Tigray War itself, which steadily continues to devour its victims with no end in sight.
Special thanks to The Fijian Armadillo.
 Deadly Ineffective: Chinese-Made Wing Loong UAVs Designate Targets For Ethiopian Su-27 Bombers https://www.oryxspioenkop.com/2021/11/deadly-ineffective-chinese-made-wing.html
 Su-27 Fighters Deployed As Bombers In Tigray War https://www.oryxspioenkop.com/2021/11/su-27-fighters-deployed-as-bombers-in.html
 UN suspends all flights to Tigray amid Ethiopian air raids https://www.aljazeera.com/news/2021/10/22/ethiopia-hits-tigray-in-fourth-day-of-air-strikes
 The Tigray Defence Forces – Documenting Its Heavy Weaponry https://www.oryxspioenkop.com/2021/09/the-tigray-defence-forces-documenting.html
 List Of Aircraft Losses Of The Tigray War (2020-2021) https://www.oryxspioenkop.com/2021/09/list-of-aircraft-losses-of-tigray-war.html
Tigray Defence Forces Display Surface-To-Air Missiles #Shorts
List Of Aircraft Losses Of The Tigray War (2020-2021)
The Tigray Defence Forces – Documenting Its Heavy Weaponry