<b>Live updates: follow the latest news on </b><a href="https://www.thenationalnews.com/world/2022/02/18/russia-ukraine-latest-news/"><b>Russia-Ukraine</b></a> Ukrainian special forces operating behind enemy lines are hitting supply columns and hampering the <a href="https://www.thenationalnews.com/world/europe/2022/04/18/russia-has-begun-offensive-for-eastern-ukraine-says-zelenskyy/" target="_blank">Russian offensive</a>, western officials have said. In addition, Ukraine's regular army’s ability to launch rapid counterattacks soon after the invaders have taken a village or town was proving decisive in buying time for the country to<a href="https://www.thenationalnews.com/world/europe/2022/04/26/germany-to-supply-ukraine-with-heavy-weaponry-for-first-time/" target="_blank"> build up its forces</a>. By contrast, significant casualties have depleted Russia’s Spetsnaz special forces, whose expertise would take considerable time to replace and rebuild, officials told a media briefing. Ukraine’s specialist troops, who are understood to have been trained by US and British special forces, have honed their tactics considerably during the fighting, creating havoc by taking out vulnerable Russian columns. Infiltrating deep behind the front line, they have been able to ambush vehicles carrying ammunition, food and vital fuel for Russia’s tanks. Sources have told <i>The National </i>that the soldiers have evolved their tactics, driving quad-bikes to cross the country quickly and planting anti-tank mines while using small drones to track and attack targets. They have called in accurate artillery fire on Russian targets causing further casualties in addition to the 15,000 Russian death toll that is “rising every day”, officials said. “Ukrainian special forces are operating behind Russian lines and exploiting the vulnerability of long supply routes to great effect,” a western official said. “It might be small scale, it might not be like defeating the entire Russian presence in an oblast [region] but all of it buys time to allow the Ukrainians to continue to build up their capabilities.” The Spetsnaz along with the Russian VDV airborne forces suffered severe losses in the early days of the war when they tried to seize Kyiv without adequate armour protection or support fire. It now appears that their losses have continued. “The Russians have lost experience in their elite forces,” an official said. “It all takes time to rebuild that expertise and that number of personnel and equipment that they need to pose a threat of a significant nature to others in the future.” While the Russians are still managing to make some advances in Donbas region, they were continually being harassed by the Ukraine army’s use of swift counteroffensives. “On Ukrainian abilities to counterattack,” the western official said, “they have proven remarkable in that regard. Even when the Russians take a village or town, Ukrainians frequently counterattack immediately so the Russians have no time to bed-in or control the situation and they're immediately on the back foot again.” Despite having tracked armoured vehicles, the Russians also seemed to be held up by heavy rainfall in eastern Ukraine, suggesting they lacked training or confidence. “They are not advancing in heavy rain. It's surprising as they have the ability to operate off the roads but have chosen not to.” While Moscow’s generals have promised to seize the entire Black Sea coast to link up to the small Russia enclave of Transnistria in Moldova, the realisation of that ambition is unlikely as they would have to take the now heavily defended city of Odesa, requiring an amphibious assault. “We've seen from the sinking of the <i>Moskva</i> [flagship cruiser] that the Russian navy is now wary of approaching that coastline for fear of a subsequent attack, so it has moved farther away from the coast.” Officials also confirmed that the West’s main effort was to “inflict cost” on Moscow by supplying weapons to degrade its military, agreeing with a British defence minister's claim that it was “completely legitimate” for Ukraine to attack targets in Russia. “We are trying to inflict cost on Russia to reduce its offensive capabilities,” the official said. “Many of our policies are designed to have that effect.”