KYIV, Ukraine (AP) – A major Russian drone and missile attack on civilian areas of Ukraine killed six people and injured at least 46, officials said Tuesday, while Moscow’s army stepped up efforts to break through Ukrainian front-line defenses in what could be the start of an anticipated spring ground offensive.

Russia fired almost 400 long-range drones at Ukraine overnight, Ukraine’s air force said, in its biggest attack in weeks. The onslaught continued into Tuesday as dozens of drones targeted the capital Kyiv during daylight.

Russia launched swarms of Iranian-designed Shahed drones, hitting at least seven cities, Ukrainian Foreign Minister Andrii Sybiha said on X.

Russia also launched 23 cruise missiles and seven ballistic missiles at Ukraine during the night, hitting at least 10 locations across the country, according to the air force. Daytime strikes injured 13 people, including three children, in the central Ukraine city of Dnipro, and another daylight attack hit an apartment block in the center of the western city of Lviv, near the Polish border, where 13 people were injured, regional officials said.

The Lviv attack set fire to the city’s 17th-century St. Andrew’s Church, which is part of a UNESCO World Heritage site, Prime Minister Yulia Svyrydenko said.

In the central city of Ivano-Frankivsk, the attack damaged maternity hospitals and about 10 apartment buildings, according to Svitlana Onyshchuk, the head of the regional military administration. Two people were killed and four injured, including a 6-year-old child, she said.

Ukrainian civilians have endured relentless barrages since Russia launched a full-scale invasion of its neighbor more than four years ago. U.S.-brokered talks between Moscow and Kyiv over the past year have brought no respite, with Russia rejecting Ukraine’s offer of a ceasefire, and in recent weeks the Iran war has diverted international attention from Ukraine’s plight.

Russia Intensifies Front-Line Attacks

On the roughly 750-mile front line snaking along eastern and southern parts of Ukraine, the short-handed defenders have been bracing for a new offensive by Russia’s bigger army as the weather improves.

The commander-in-chief of Ukraine’s armed forces, Gen. Oleksandr Syrskyi, said Russian troops have in recent days made simultaneous attempts to break through defensive lines in several strategic areas.

“Fierce fighting unfolded along the entire line of contact,” Mr. Syrskyi said Monday on the Telegram messaging app, with Russia launching 619 attacks in four days.

“The occupiers are attempting to bring up new units and are preparing to continue attacks,” Mr. Syrskyi said, adding that Ukraine had deployed reinforcements to counter the assaults.

It was not possible to independently verify the battlefield claims.

The Institute for the Study of War, a Washington-based think tank, said Syrskyi’s report backed up its assessment that Russia’s spring-summer offensive is now underway.

Russia escalated its strikes from March 17 and has moved heavy equipment and more troops to the front line, the ISW said late Monday.

Each year, as the weather improves, Russia has moved its grinding war of attrition up a gear. However, it has been unable to capture cities and has made only incremental gains across rural areas. Russia occupies about 20 percent of Ukraine. That includes the Crimean Peninsula, which Russia seized in 2014.

Ukrainian Soldier Says Front Line Situation Is ‘Tense But Not Critical’

A Ukrainian soldier fighting near the city of Lyman in Ukraine’s eastern Donetsk region, whose complete capture is one of Russian President Vladimir Putin’s main invasion goals, said Russian forces have intensified assaults in recent days but failed to achieve a breakthrough, despite increasing bombardments and repeated ground attacks.

Russian troops had earlier sought to isolate Lyman by targeting logistics routes before escalating their offensive, according to the soldier, who gave only his call sign King, in keeping with the rules of the Ukrainian military.

Ukrainian units repelled initial assaults, destroying advancing Russian columns and inflicting significant losses in armored vehicles and personnel, he said. In response, Russian forces have increased airstrikes on the town, including the use of powerful glide bombs.

“The situation is tense, but not critical,” King said.

Drones Allow Ukraine to Fend Off Russian Ground Attacks

Ukraine has developed advanced drone technology to make up for its shortage of infantry.

Amid the Middle East conflict, Kyiv is offering Ukraine’s battle-tested drone defenses to U.S. and Gulf partners, hoping to trade that know-how for scarce Patriot air defense missiles it needs to fend off Russia’s barrages.

Ukraine has also used its domestically produced long-range drones to hit areas of Russia that support Moscow’s war effort. Russian air defenses intercepted 55 Ukrainian drones overnight over Russian regions, the annexed Crimea and the Black Sea, the Russian Defense Ministry reported Tuesday.