What to Know About Russia’s Offensive in Ukraine’s Northeast

Ukrainian soldiers were engaged in fierce fighting on Monday in their country’s northeast, trying to fend off an advance by Russian forces who surged across the border last week to open a new line of attack near the city of Kharkiv.

Russian airstrikes on Monday were pounding Vovchansk, a small town about five miles from the border, according to Denys Yaroslavsky, a Ukrainian officer currently fighting there.

“They’re dropping five to seven bombs every three minutes,” Mr. Yaroslavsky said in a phone interview on Monday, referring to the Russian bombardment.

Vovchansk had a prewar population of about 17,000 people, and local officials have been scrambling to evacuate the estimated 200 to 300 remaining residents. Hryhoriy Shcherban, a volunteer who was in Vovchansk on Monday morning, said that he had received more than 200 requests for evacuation overnight.

“We are driving around trying to find the addresses. Russia is shelling the evacuation road,” he said. “You can hear explosions all the time.”

The advance on Vovchansk followed weeks of warnings from Ukrainian officials that Russia was massing forces on the border with the aim of launching a new offensive in the northeast. Those warnings became a reality early Friday morning when Russian troops streamed across the border along two main lines — one immediately north of Kharkiv, Ukraine’s second-largest city, after the capital Kyiv, and the other about 12 miles to the east, around Vovchansk.

Here’s what to know about the current situation.

Rapid gains

The Ukrainian military acknowledged early Monday that Russian forces had seized a number of settlements in a rapid offensive.

“The enemy is currently achieving tactical success,” the General Staff of Ukraine said in a statement.

Russian forces have so far managed to capture at least nine villages and settlements, pushing about five miles into Ukrainian territory and seizing some 50 square miles of land, according to online maps of the battlefield posted by the Institute for the Study of War, a Washington-based think tank.

Military experts and Ukrainian officials say that the Russian troops have so far mostly advanced through lightly defended and largely depopulated territory, explaining the relatively quick progress. The border in northeastern Ukraine has been subject to regular Russian shelling throughout the war, they note, which has made it difficult to establish fortified positions and has driven many civilians to flee.

Still, Russian forces are approaching more populated areas, and the fight may increase in intensity. The local authorities have already evacuated close to 6,000 people since Friday, according to Oleh Syniehubov, head of the Kharkiv region’s military administration.

What’s the goal?

Ukrainian forces were already stretched thin trying to defend a 600-mile front line running from the east of Kharkiv to the city of Kherson on the Black Sea. With the new offensive, the Russian Army is trying to further strain the Ukrainian lines and eventually break through, military experts say.

Franz-Stefan Gady, a Vienna-based military analyst, said that Russia was trying to divert Ukrainian troops from the southeastern Donbas region to make it easier for Russian troops to capture territory there.

Russia’s main objective, according to Mr. Gady, is to draw forces away from Chasiv Yar, a Ukrainian stronghold that Russian forces have been assaulting for weeks. The town lies on strategic high ground and is key to defending the Ukrainian-controlled part of the Donbas.

Ukraine has already sent reinforcements to the northeast, including from the 92nd Assault Brigade, according to Pasi Paroinen, an analyst from the Black Bird Group, an organization based in Finland that analyzes satellite imagery and social media content from the battlefield.

That unit has recently been fighting in Chasiv Yar, according to Mr. Paroinen, who said it was possible that Ukraine had drawn from elements of the brigade that were resting in Kharkiv, their home garrison.

Mykhailo Samus, the deputy director of the Ukrainian Center for Army, Conversion and Disarmament Studies, a military research organization in Kyiv, said the situation had “as of now stabilized,” with Ukrainian forces managing to slow down the Russian advance.

But Mr. Samus and Mr. Paroinen both said that Russia had yet to commit large numbers of troops to the offensive — probably deploying just a few thousand soldiers — and that much would depend on Moscow’s next move.

What’s happening elsewhere?

Russian forces have in recent days also made marginal gains in southeastern Ukraine, entering the town of Krasnohorivka last week, Ukrainian officials said.

They have also slightly expanded their control over villages surrounding the city of Avdiivka, which fell to Russia in February. Experts say Russian forces might look to exploit their gains in that area to move further north toward Chasiv Yar, which is about 25 miles away, in a pincer movement.

Elsewhere, the Russian authorities said on Monday that Ukrainian shelling had killed 19 civilians in the Belgorod region of Russia, across the border from Kharkiv.

In one particularly deadly incident, the Russian Defense Ministry said fragments from an intercepted Ukrainian missile had struck an apartment building in the region on Sunday. Vyacheslav Gladkov, the Belgorod governor, said that 15 bodies had been found in the rubble. The claims could not be independently verified; Ukrainian officials denied firing on residential areas.