Russian forces struck a cafe in a key front-line area in northeastern Ukraine on Saturday, killing two civilians and wounding a third, regional officials said.

The shelling near the city of Kupiansk came as UK officials said that Russia may try to retake the area, which was captured by Kyiv in a lightning counteroffensive last September after more than six months of Russian occupation. Fierce fighting there earlier this month prompted mandatory evacuations and fears of a second Russian takeover.

Russian shells on Saturday morning struck the cafe in Podoly, an eastern suburb of Kupiansk, regional Gov. Oleh Syniehubov said in a Telegram post. He added that rescue teams were working at the site.

UK military intelligence assessed that Russia may “increase the intensity of its offensive efforts” around Kupiansk and nearby Lyman in an attempt to take pressure off its forces near Bakhmut and in the Zaporizhzhia region, where a Ukrainian counteroffensive has reportedly made gradual gains.

Workers clean a part of a damaged skyscraper in the 'Moscow City' business district after a reported drone attack in Moscow. Photo / AP

Igor Konashenkov, a spokesman for the Russian defence ministry, said in a regular briefing Saturday that Moscow’s forces had “improved their position along the front line” in the Kupiansk area and repelled five Ukrainian assaults over the previous day. He did not give further details regarding any troop movements.

Earlier this month, Ukrainian authorities ordered a mandatory evacuation of nearly 12,000 civilians from 37 towns and villages around Kupiansk, citing a concerted effort by Russian troops to punch through the front line.

After the Russian occupiers left Kupiansk last year, Ukrainian authorities said they found torture chambers and mass graves in the region.

Ukrainian officials have so far reported limited advances in Kyiv’s large-scale counteroffensive launched in early June, including in the southern Zaporizhzhia region and on the outskirts of Bakhmut, the eastern city that became the site of the war’s longest and bloodiest battle before falling to Moscow in May.

A Washington-based think tank said late Friday that Ukrainian forces were pushing forward in Zaporizhzhia after advancing into the village of Robotyne earlier this week. The Institute for the Study of War in its latest assessment cited pro-Kremlin military bloggers expressing concern over a lack of reinforcements and troop locations in the area, while the Ukrainian General Staff that same day claimed unspecified further successes south and southeast of Robotyne.

Also on Saturday, a new drone attack on Moscow forced an early morning temporary shutdown of all three major airports serving the city, Russian state media reported. Officials blamed Ukraine for what appeared to be the latest of near-daily strikes on the Russian capital and the surrounding region.

Kyiv has since early this year sought to take the 18-month war into the heart of Russia, also saying recently that it was behind strikes on Russian military assets far behind the front lines.

Russia’s defence ministry and Moscow Mayor Sergey Sobyanin said that a drone was shot down over the Istra district of the Moscow region, some 50km west of Red Square. Sobyanin said in a Telegram post that there were no immediate reports of any casualties or damage.

According to Russia’s state Tass agency, the Sheremetevo, Domodedovo and Vnukovo airports all suspended flights for over an hour early on Saturday.

Russian Telegram channels on Saturday posted videos, some of them apparently from home security cameras, of what they claimed was Russian air defence downing the drone. One video shows a car parked outside what appears to be a suburban home, its alarm beginning to blare seconds after two loud blasts sound in the distance.

Russia’s defence ministry that same day blamed Ukraine for the attack. As of Saturday morning, Ukrainian authorities had not said whether Kyiv had any involvement.

Russia and Ukraine traded multiple drone attacks earlier this week, with Kyiv apparently targeting Moscow and the Kremlin’s forces launching another bombardment of Ukrainian grain storage depots in what have recently become signature tactics.

Also this week, Kyiv claimed it had destroyed a key Russian S-400 surface-to-air missile defence system in occupied Crimea. Ukrainian media also claimed that Ukrainian saboteurs co-ordinated by Kyiv’s military intelligence services carried out a pair of recent drone attacks that destroyed and damaged bomber aircraft at air bases deep inside Russia.

Later on Saturday, Russia’s defence ministry said in a separate statement that another drone was brought down as it approached the Russian city of Belgorod, some 45km from the Ukrainian border. It did not mention any casualties or damage.

People look at a large column of burnt out and captured Russian tanks and infantry carriers which have been on display on the central Khreshchatyk boulevard. Photo / AP

Belgorod regional Gov. Vyacheslav Gladkov accused Ukrainian forces of shelling a border village using cluster munitions, wounding six civilians. Gladkov did not provide visual evidence for the use of the controversial and widely banned weapons, which contain dozens of small bomblets that scatter shrapnel over a wide area.

Kyiv last month began receiving cluster bombs from the US, but has pledged to use them only to dislodge groups of enemy soldiers. Ukrainian officials have regularly accused Moscow of firing cluster munitions at residential areas, while Russian regional authorities have reported Ukrainian cross-border attacks in which civilians were hurt.

Ukraine’s air force, meanwhile, reported early on Saturday that two Iranian-made “Shahed” drones fired by Russian troops were shot down during the night over the country’s northeast.

In Ukraine’s front-line Kherson region in the south, local Gov. Oleksandr Prokudin reported that an 83-year-old woman died in a hospital after suffering burn wounds as Russian forces overnight shelled the riverside village of Olhivka. Also on Saturday, the Kherson regional administration reported that Russian shelling damaged a hospital in the province’s namesake capital, blowing out doors and windows but causing no casualties.