The eastern Ukrainian town of Avdiivka is increasingly becoming a flashpoint in the conflict, where fighting remains intense even when the front lines have barely moved for months.
Russia appears to have made tactical advances in the outskirts of the embattled town as Ukraine claims it is inflicting heavy losses on assaulting troops.
With the weather getting colder and both sides struggling for a breakthrough, Ukraine’s president also announced he would shore up his country’s defenses.
Here is what you need to know about the past week in Ukraine.
Zelensky bolsters front line defenses
Ukraine is stepping up efforts to bolster defenses and fortifications across the country.
President Volodymyr Zelensky announced a countrywide initiative to strengthening defensive positions on Thursday, outlining the main areas of focus.
The primary effort will be where heavy fighting is taking place on front lines in the Avdiivka-Mariinka direction in eastern Donetsk, and the defensive line near Kupiansk in the north-eastern Kharkiv region.
Defensive fortifications will be bolstered along all of Ukraine’s northern territory which borders Belarus and Russia.
Positions will also be strenegthened in the southern Kherson region where Ukrainian troops are continuing their attempts to widen a bridgehead in the Russian occupied bank of the Dnipro River.
Analysts warn that building up fortifications with active shelling in some areas and harsh winter conditions can pose a challenge.
Zelensky’s announcement comes as the war enters what Ukraine’s top military chief called “positional war”— a maturing phase of the conflict where neither side has the ability to generate force overmatch or significant breakthrough leading to more static and solidified frontlines.
Analysts have pointed to Russian defensive positions which managed to keep Ukraine’s summer counteroffensive from gaining ground as an example of the effectiveness of fortified lines.
As both side dig in, it makes seizing significant territory without huge attrition – where depth of manpower and equipment becomes a determining factor – harder and harder.
‘It gets worse and worse’: The fight for Avdiivka
Russian forces continued their attempts to fully encircle the town of Avdiivka in Ukraine’s eastern Donetsk region where harsh winter conditions have reportedly complicated maneuvers for both Ukrainian and Russian forces.
Pro-Russian bloggers have reported tactical advances in the industrial zone in the southeast and the rail lines in the northwest of the town throughout the week as the Ukrainian military claimed they are holding defensive positions.
Russia maintains air superiority and has been making use of guided aerial bombs, retrofitted Soviet-era munitions with high explosive loads that are released by Russian warplanes outside the range of air defenses, as high velocity winds and snow limit the use of drones.
A local official said Russia has been focusing on trying to get the high ground in the industrial zone in Avdiivka but has not been successful. Ukraine claims defensive actions in and around the town are inflicting heavy losses on Russian troops and equipment.
Ukrainian police have been helping locals evacuate. Some 1,300 civilians remain in Avdiivka, which has been a front line town since 2014.
An elderly couple who were evacuated from Avdiivka this week recounted the decision to leave. “It gets worse and worse day after day… we get almost no sleep. Shelling and shelling and shelling…We thought we could wait, that things would get better, but we have run out of patience,” she said. “At least now, we can get some sleep.”
Some essential workers are in the city to provide services for the remaining civilians, including two doctors and four nurses, according to the head of local military administration Vitalii Barabash. If needed “most of them have already packed their bags and are ready to leave within an hour.”
Ukraine claims it sabotaged two Russian trains in Siberia
Ukraine’s Security Service (SBU) is responsible for explosions on two trains traveling along a strategic rail route in eastern Russia this week, a Ukrainian defense source claimed Friday.
If confirmed, the strikes show Kyiv’s intent and ability to disrupt Russian logistics thousands of miles away from the frontlines of Moscow’s war in Ukraine.
With train traffic rerouted around the tunnel, the SBU on Thursday targeted the second train as it passed over the nearby Devil’s Bridge, according to the source.
Both explosions were the result of planted “explosive devices,” the source claimed.
“The Russians have fallen into the SBU’s trap twice,” the source said. The twin bombings were a “special operation to disable this important railroad,” the source added.
Russian Telegram channels reported news of two train fires in the area. Videos circulated by some Russian telegram channels show wagons on fire along a rail track, although it is not immediately clear which incident the videos are from.
Russia has not immediately called Wednesday’s explosion an attack or blamed Ukraine for what it has so far characterized as “a cargo train fire.” Unofficial Russian media reported investigators are looking into the possibility of “sabotage.”
The Ukrainian source said the Russians use the railroad for “military logistics” and characterized the route as “the only major railroad connection between Russia and China.” The targeted trains were carrying fuel, the source said.
Ukrainian analysts said the route is critical for Russian deliveries from North Korea and China.
Finland closes border with Russia after migrant surge
The warning light turned from green to red at the last operating checkpoint on the Finnish side of the border with Russia this week as Moscow’s international isolation continues to grow.
Finnish television announced the closure: “The entire eastern border of Finland is now closed.
The crossing was one of the few entry points for Russians after many Western countries shut their air space and borders to Russian planes in response to the Ukraine invasion.
The 1,340-kilometer- (833-mile-) long border will be closed for at least two weeks.
Finland’s decision came as more and more third country nationals started arriving from Russia. Helsinki accused Russia of weaponizing refugees and asylum seekers and called the arrivals a “Russian hybrid operation.”
NATO chief Jens Stoltenberg accused Russia of using migration as a “tool” to create “pressure” along its border with Finland. “We have seen them using energy, we have seen them using cyber attacks, we have seen them using different kinds of clandestine operations to try and undermine our democracies. The fact that Russia is using migration as a tool is now another example of the attempt to put pressure on neighbors,” Stoltenberg said at a news conference in Brussels.
Russia called Finland’s decision to close all border checkpoints “irrational.”
Ukrainian spy chief’s wife hospitalized after apparent poisoning
Marianna Budanova, who is married to Ukraine’s defense intelligence (GUR) chief Kyrylo Budanov, was hospitalized with apparent heavy metals poisoning the GUR said, raising concerns that Russia may have the capacity to target senior Ukrainian leadership.
The seriousness of Budanova’s condition was not immediately apparent.
Russia — and the Soviet Union before that — has been known to carry out extra-territorial poisonings against its enemies.