Russia’s President Vladimir Putin on Sunday proposed replacing Sergei Shoigu as defense minister and appointed him as secretary of Russia’s national security council.

The appointment comes after Putin proposed appointing Andrei Belousov as the country’s defense minister in place of Shoigu, who has served in the post for years. The reshuffle comes as Putin starts his fifth presidential term and as the war in Ukraine drags on for the third year

In line with Russian law, the entire Russian Cabinet resigned on Tuesday following Putin’s glittering inauguration in the Kremlin.

The announcement came as thousands more civilians have fled Russia’s renewed ground offensive in Ukraine’s northeast that has targeted towns and villages with a barrage of artillery and mortar shelling, officials said Sunday.

The intense battles have forced at least one Ukrainian unit to withdraw in the Kharkiv region, capitulating more land to Russian forces across less defended settlements in the so-called contested gray zone along the Russian border.

By Sunday afternoon, the town of Vovchansk, among the largest in the northeast with a prewar population of 17,000, emerged as a focal point in the battle.

Volodymyr Tymoshko, the head of the Kharkiv regional police, said that Russian forces were on the outskirts of the town and approaching from three directions.

“Infantry fighting is already taking place,” he said.

A Russian tank was spotted along a major road leading to the town, Tymoshko said, illustrating Moscow’s confidence to deploy heavy weaponry.

An Associated Press team, positioned in a nearby village, saw plumes of smoke rising from the town as Russian forces hurled shells. Evacuation teams worked nonstop throughout the day to take residents, most of whom were older, out of harm’s way.

At least 4,000 civilians have fled the Kharkiv region since Friday, when Moscow’s forces launched the operation, Gov. Oleh Syniehubov said in a social media statement. Heavy fighting raged Sunday along the northeast front line, where Russian forces attacked 27 settlements in the past 24 hours, he said.

Analysts say the Russian push is designed to exploit ammunition shortages before promised Western supplies can reach the front line.

Ukrainian soldiers said that the Kremlin is using the usual Russian tactic of launching a disproportionate amount of fire and infantry assaults to exhaust their troops and firepower. By intensifying battles in what was previously a static patch of the front line, Russian forces threaten to pin down Ukrainian forces in the northeast, while carrying out intense battles farther south where Moscow is also gaining ground.

It comes after Russia stepped up attacks in March targeting energy infrastructure and settlements, which analysts predicted were a concerted effort to shape conditions for an offensive.