At least seven people, including three children, were killed in a Russian airstrike on western Ukraine's Lviv on Wednesday as Moscow intensified attacks across the country.

The attack comes a day after missiles hit the central city of Poltava, killing at least 41 people, in one of the single deadliest bombardments of Russia's invasion, which has stretched into its third year.

"In total, seven people died in Lviv, including three children," Internal Affairs Minister Igor Klymenko wrote on Telegram, upping the previously reported toll.

Sirens rang out over the city of Lviv before sunrise Wednesday, according to Mayor Andriy Sadovy, who advised people to take shelter as air defenses worked to down a barrage of missiles.

The missile attack wounded 40 people, the prosecutor's office said and damaged residential buildings in the city's historic center as well as schools and medical facilities.

President Volodymyr Zelenskyy denounced what he called "Russian terrorist strikes on Ukrainian cities."

He also repeated calls for Western partners to provide Ukraine with long-range weapons to "respond justly" to the attacks.

The western city of Lviv has largely been spared the worst of the fighting over the 2 1/2 years of war but last week, Russian strikes targeted its energy infrastructure causing outages, according to officials.