Oleksi, a 44-year-old Ukrainian soldier from the 151st Battalion, raises the drone into the sky, and in just over a minute, the device advances a little over a kilometer at an altitude of approximately 60 meters, entering Kupiansk. The unmanned aircraft’s front camera shows the destruction and desolation that reign in this town in the Kharkiv region of northeastern Ukraine, control of which is currently being fought over by the two armies. Testimonies gathered by EL PAÍS, during a visit in which access was only authorized as far the city limits, confirm that every street, every building, and even every ruin is being fought over. Around 80% of the town has been destroyed.

Kupiansk is not only the most important urban center in eastern Kharkiv, but also a strategic point close to the Luhansk region, almost entirely in the hands of invaders, and about thirty kilometers (18 miles) from the Russian border. This enclave blocks a possible future Ukrainian offensive on Luhansk, not only cutting off Kharkiv’s logistical route to the neighboring region but also bringing the roads connecting Kharkiv and Donetsk to within artillery and Kab (guided aerial bomb) range. Therefore, the complete capture of Kupiansk would represent a significant strategic triumph for the Russians, whose advances in Dobropillya and Pokrovsk (both in Donetsk) have been slowed.

In the drone’s aerial view some explosions can be seen, but there is no visible troop movement through the streets of Kupiansk. It is here that the Russians have attempted a surprise attack in recent weeks by sending dozens of soldiers through underground gas pipelines. Many have been killed. Others are eking out their survival with little infrastructure or support, trying to pass themselves off as Ukrainian civilians, according to sources on the ground. “The situation is critical, with Russian sabotage and reconnaissance groups present in the city and an anti-sabotage operation underway,” Mayor Andrii Besedin acknowledged in late September.

The operation, according to the Ukrainian army, was halted after they flooded the pipelines and disabled them. But Kupiansk, which was under Moscow’s control for six months in 2022, remains contested in a seemingly endless battle. The trickle of Russians continues to arrive via various routes. Part of the northern part of the town, where a total of about 600 residents — almost all of then elderly — remain out of the 30,000 pre-war inhabitants, appears to be in the hands of the invaders, according to the DeepState website map updated by Ukrainian military analysts. The only way to carry out evacuations is to get the residents, who live without water, electricity, gas, or any other services, to leave the town on foot, the mayor adds.

Oleksi, a 44-year-old soldier, prepares a drone at his underground position on the outskirts of Kupiansk.Luis de Vega

“We recognize them [the Russians] fairly easily,” says Oleksi, the drone pilot. “By their haircuts, the way they move, trying not to be too visible… And” — he smiles — “because they sometimes carry backpacks and are armed. They are young, between 18 and 40 years old.” He adds that their survival is also complicated by the lack of food and water, as well as the lack of electricity to charge their devices and communicate. Oleksi doesn’t hide the fact that they have sometimes observed residents of Kupiansk assisting the Russian military. When they detect the enemy, they notify central command, and from there, the infantry is mobilized.

Diesel (a nom de guerre), 47, and his comrades from the 151st Battalion have occasionally traveled to the coordinates provided by their colleagues who comb the skies with drone cameras. But they say the missions are extremely dangerous because the Russians also control the area with their equipment. “Entering the city now is very complicated,” acknowledges this enormous soldier, who covers his face as a condition for being photographed.

That’s why advances through the urban area of Kupiansk to try to end enemy skirmishes have stopped being made by vehicle. Fedir, the 50-year-old military driver transporting the reporter and his interpreter, says he hasn’t re-entered the town and is simply trying to get the men as close as possible.

At the door of a house in a rural area on the outskirts of Kupiansk, the car Diesel and his companions were using until recently lies heavily damaged. He says they were miraculously saved when the Russian drone hit them directly on one of the streets. Movements along the area’s roads—sometimes covered with mesh netting to prevent attacks—are measured and controlled as much as possible, always with a drone-detecting device on hand in case they need to take cover.

A road near Kupiansk, which has been disputed by Russians and Ukrainians for months.Luis de Vega

Diesel recounts how, during one of the missions, almost in the city center, they were able to capture a prisoner of war. When interrogated, he said he was originally from the Moscow region and had made his way through the gas pipelines. He had only enlisted two months earlier after accepting an offer from the Russian Ministry of Defense, which allowed him to avoid prison for drug trafficking. “We found four Russian soldiers in civilian clothes. We tried to attack them on two consecutive days. Two were killed on the first day by the drones (which supported them from above). The next day, one became very aggressive, and we killed him. Then the other surrendered,” Diesel explains.

The prisoner, according to the account of the soldier who captured him, told them that his superiors had ordered them to remove all Russian identification and try to pass themselves off as Ukrainian civilians. He also said that the order was not to fight, but to take up positions and conduct surveillance and intelligence work. The invaders’ intention was to try to bring in several hundred men and then proceed with the assault on Kupiansk.

Soldiers of the 151st Ukrainian Battalion in an underground position near Kupiansk.Luis de Vega

The Russian, who was wounded in the arm and required a bandage, explained that he had managed to enter the city on September 1, about two weeks before his arrest. The prisoner recounted that many Russians were trying to access the tunnels in small groups of 10 or 12. In his case, they first went out to a wooded area half-burned by the effects of the fighting and separated into smaller groups of two or three.

Diesel confirms that there are hardly any civilians left, but that it is necessary to identify and locate them as often as possible. “Last time I saw a couple of grandmothers preparing food in the garden,” he notes, expressing his surprise that they are still in Kupiansk amid the drones and artillery. “We have divided the city into areas and monitor the remaining civilians, their documents… and sometimes we have brief conversations with them. If they are men and don’t have Ukrainian papers, we take them to find out who they are. We have to constantly monitor the houses, apartments, and basements to see who is there, or on the rooftops,” the soldier explains.

The gas pipeline route is risky, uncomfortable, and complicated, says Oleksi. He doesn’t believe it was a decisive strategy in the battle for Kupiansk, although he does acknowledge that the Ukrainian army is still short on troops in this area. With this underground route closed, he explains, “they now try to reach [the city] through forests or rivers, and it’s harder to pinpoint how they get there.” From his position several meters underground, Oleksi loads two bombs weighing approximately half a kilo into a new drone that he directs toward Kupiansk. It’s routine in a war in which these devices have largely decimated artillery positions.

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