Kyiv said on Saturday its forces had made lightning-fast gains in the east of the country in a shock counteroffensive to retake areas that fell to Russia shortly after Moscow’s February invasion.

Meanwhile, German Foreign Minister Annalena Baerbock made a surprise visit to the Ukrainian capital to demonstrate Berlin’s support for Ukraine in its fight against Russia.

“Ukrainian troops are advancing in eastern Ukraine, liberating more towns and villages. Their courage, coupled with Western military support, is bringing amazing results,” Foreign Ministry spokesman Oleg Nikolenko said in a statement on social media.

“It is crucial to keep sending arms to Ukraine. Defeating Russia on the battlefield means winning peace in Ukraine,” he added.

His assessment of the pace of Ukraine’s gains came after President Volodymyr Zelenskyy announced late Friday that his forces had retaken about 30 towns and villages in the northeastern Kharkiv region as part of the sweep.

Ukraine’s advance appears to have caught Russian troops largely unprepared.

Moscow made the surprise announcement that it was sending reinforcements to Kharkiv, with images in state media showing tanks, artillery and support vehicles moving in columns on dirt roads.

The largest city to date to fall back into Ukrainian hands is Balakliya, with an estimated pre-war population of around 30,000.

According to unconfirmed reports, the Ukrainians continued to advance east.

The capture of urban hubs like Kupiansk and Izium would be a major blow to Russia’s ability to effectively deliver positions on the Eastern Front.

In a village captured by the advancing Ukrainians, power poles were toppled, cables scattered on the ground and houses gutted, AFP journalists reported.

“It was scary,” said Anatoly Vasiliev, 61, recalling the battle earlier this week in which Ukrainian troops retook the village from the Russians.

“There were bombings and explosions everywhere.”

Baerbock was in Kyiv on Saturday for her second trip to Ukraine, which comes a week after Ukrainian Prime Minister Denys Shmygal’s trip to Berlin, where he repeated Kiev’s call for arms.

“I traveled to Kyiv today to show that they can continue to count on us. That we will stand by Ukraine with arms supplies and humanitarian and financial support for as long as necessary,” she said.

In recent weeks, Germany has sent howitzers, rocket launchers and anti-aircraft missiles to Kyiv, part of an arsenal of western-supplied weapons that observers say have hampered Russia’s supply and command capabilities.

Baerbock’s visit follows a trip by US Secretary of State Antony Blinken, who promised Ukraine a nearly $3 billion military package.

Meeting in Brussels with NATO Secretary General Jens Stoltenberg, Blinken said Russia’s push to send reinforcements shows Moscow is paying “huge costs” in its attempt to seize and then hold Ukrainian territory.

However, Russian forces still inflicted heavy damage with a shelling campaign in the city of Kharkiv and in the industrial Donbass region to the east.

Oleg Synegubov, the Kharkiv chief, said Russian shelling wounded 14 civilians.

Pavlo Kyrylenko, the head of Donetsk region, which is part of Donbass, said Russian shelling has now claimed two lives.