KATIE DAVIES, SAMYA KULLAB AND VASILISA STEPANENKO -- Russia’s President Vladimir Putin began a Cabinet shakeup on Sunday, proposing the replacement of Sergei Shoigu as defence minister as he begins his fifth term in office.

In line with Russian law, the entire Russian Cabinet resigned on Tuesday following Putin’s glittering inauguration in the Kremlin, and most members have been widely expected to keep their jobs, while Shoigu's fate appeared uncertain.

Putin signed a decree on Sunday appointing Shoigu as secretary of Russia's national security council, the Kremlin said. The appointment was announced shortly after Putin proposed Andrei Belousov to become the country’s defence minister in place of Shoigu.

Belousov's candidacy will need to be approved by Russia's upper house in parliament, the Federation Council. It reported Sunday that Putin introduced proposals for other Cabinet positions as well but Shoigu was is the only minister on that list who is being replaced. Several other new candidates for federal ministers were proposed Saturday by Prime Minister Mikhail Mishustin, reappointed by Putin on Friday.

Shoigu's deputy Timur Ivanov was arrested last month on bribery charges and was ordered to remain in custody pending an official investigation. The arrest of Ivanov was widely interpreted as an attack on Shoigu and a possible precursor of his dismissal, despite his close personal ties with Putin.

Andrei Belousov

Kremlin spokesman Dmitry Peskov said Sunday that Putin had decided to give the defence minister role to a civilian because the ministry should be “open to innovation and cutting-edge ideas” and Belousov, who until recently served as the first deputy prime minister, is the right fit for the job.

Tatiana Stanovaya, a senior fellow at the Carnegie Russia Eurasia Center, said in an online commentary that Shoigu’s new appointment to Russia’s Security Council showed that the Russian leader viewed the institution as a political holding space.

Figures such as former Russian president Dmitry Medvedev have also been appointed to the security council: Medvedev has served as the body’s deputy chairman since 2020.

“The Security Council is becoming a reservoir for Putin’s “former” key figures — people who he can’t let go, but doesn’t have a place for,” Stanovaya wrote on social media.

The announcement of Shoigu's new role came as 12 people were reported dead and 20 more wounded in Russia's border city of Belgorod, where a section of a residential building collapsed after what Russian officials said was Ukrainian shelling.

In Ukraine, 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.

Ukrainians going to evacuation points

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.

Meanwhile, a 10-story apartment building partially collapsed in Belgorod near the border, killing at least 12 people and injuring 20 others. Russian authorities said the building collapsed following Ukrainian shelling. Ukraine hasn't commented on the incident.

The Russian Defence Ministry said Sunday that its forces had captured four villages on the border along Ukraine’s Kharkiv region, in addition to five villages reported to have been seized on Saturday. These areas were likely poorly fortified because of the dynamic fighting and constant heavy shelling, easing a Russian advance.

Ukraine’s leadership hasn't confirmed Moscow’s gains. But Tymoshko, the head of the Kharkiv regional police, said that Strilecha, Pylna and Borsivika were under Russian occupation, and it was from their direction they were bringing in infantry to stage attacks in other embattled villages of Hlyboke and Lukiantsi.

Associated Press writers Samya Kullab in Kyiv, Ukraine; Vasilisa Stepanenko in Vilcha, Ukraine and Katie Marie Davies in Manchester, England contributed to this report