Ukrainian forces targeted the Russian-occupied city of Melitopol deep within the front lines on Wednesday, attacking a railway depot and causing power outages. This comes as Kyiv hints at a potential counteroffensive against worn-out Russian forces, who have made little progress in their winter campaign.

Unverified images online show explosions and streaks of contrails in Melitopol, the base of the Russian-controlled administration in Zaporizhzhia, one of the five Ukrainian provinces Russia claims to have annexed. The city's exiled mayor confirmed the explosions, while Russia's TASS news agency reported damage to a railway depot and power outages in the city and nearby villages.

Melitopol, a crucial railway logistics hub for Russian forces in southern Ukraine, is home to around 150,000 people and is part of the land bridge connecting Russia to the occupied Crimea peninsula. The weapons Ukraine used for the strike remain unknown, but the city is within range of Ukraine's HIMARS rockets and newer weapons like air-launched JDAM bombs and ground-launched GLSDB munitions supplied by the United States. Russia reported shooting down a GLSDB for the first time on Tuesday.

This strike could disrupt Moscow's rear logistics as Kyiv signals a possible counterattack against Russian forces, who have failed to secure significant victories despite the bloodiest fighting of the war. Melitopol is located south of the Russian-held Zaporizhzhia nuclear power plant, which was visited by U.N. nuclear agency chief Rafael Grossi on Wednesday. Grossi reiterated calls for a safe zone around the plant, noting the situation has not improved and nearby fighting has intensified.

Ukrainian forces have primarily been on the defensive since their last significant advance nearly five months ago. Meanwhile, Moscow initiated a winter offensive, deploying hundreds of thousands of reservists and tens of thousands of convicts for its Wagner private army. As winter transitions to spring, questions arise about the sustainability of Russia's offensive and when Ukraine will counterattack.

Signs of the Russian assault's weakening are evident, as Ukraine's general staff reports a decline in the average number of daily Russian attacks on the front line for four consecutive weeks since March's start. Moreover, Reuters journalists near the front lines west of Bakhmut and further north have observed a significant decrease in Russian attack intensity.

Anticipation is building within Ukraine for a potential counteroffensive. On Wednesday, lawmaker Oleksiy Honcharenko shared a video on social media featuring dozens of manned Ukrainian fighting vehicles with engines running in an open field. The video's authenticity and filming date could not be immediately verified.

Despite enormous casualties on both sides, Russia has made no substantial gains, and Ukrainian and Western officials suspect the Russian attacking force will soon be exhausted. Russian officials claim their forces continue to make progress in street-by-street fighting in Bakhmut, their primary target for months. However, they have failed to encircle the city and force a Ukrainian withdrawal, which appeared likely weeks ago.

British military intelligence stated on Wednesday that Ukrainians had successfully pushed Russians back from the main supply route to Bakhmut and that Russian assaults in the city were diminishing. Moscow also launched a new attack on Avdiivka, a smaller city to the south, which Britain said resulted in substantial Russian armor losses without making gains.

This week, the first full units of Western main battle tanks arrived in Kyiv, fulfilling a promise made two months ago to spearhead a counteroffensive when warmer weather dries Ukraine's notorious black mud. In response, Russia's RIA news agency reported that Moscow has sent hundreds of new and refurbished tanks to its troops.

In Kyiv, hundreds of worshippers from a historically Moscow-aligned minority branch of the Orthodox Church gathered at a thousand-year-old monastery on Wednesday for what could be their last service before eviction. The group, known as the Ukrainian Orthodox Church, severed ties with Moscow last year following the invasion but has been accused by Kyiv authorities of harboring Russian agents, a claim they deny. Most Ukrainian believers belong to the separate Orthodox Church of Ukraine, which broke from Moscow years earlier.

Russian Deputy Foreign Minister Sergei Ryabkov stated that a plan announced this week to deploy tactical nuclear weapons in Belarus would force NATO to assess the situation's seriousness. Moscow has repeatedly hinted at the possibility of the conflict turning nuclear, a threat Western governments largely dismiss as intimidation aimed at curtailing military aid to Kyiv.

U.S. President Joe Biden described the prospect as "worrisome," but Washington has not observed any signs of Russia being closer to using tactical nuclear weapons in Ukraine. On Wednesday, Russia's defense ministry announced the commencement of exercises involving its Yars intercontinental ballistic missile system and several thousand troops.

Ryabkov also revealed that Russia, which suspended participation in its last arms control treaty with the United States last month, is no longer providing Washington with any information about its nuclear activities.