Russia launched a broad aerial assault at targets across Ukraine on Monday, the second wide-ranging attack in three days, as fighting appeared to intensify ahead of an anticipated Ukrainian counteroffensive.

Explosions echoed in the skies above the Ukrainian capital, Kyiv, and other parts of the country before dawn as Ukrainian air defences shot down 15 of 18 Russian cruise missiles, according to the Ukrainian military. The alert in the capital lasted for about three hours until the authorities said that “all enemy missiles and drones were destroyed in Kyiv airspace”.

There were no initial reports of civilian casualties in the missile barrage, which came as Ukrainian forces stepped up efforts to strike Russian targets behind the front lines ahead of an expected push to recapture lost territory with the support of newly delivered, powerful weapons from Western allies.

Hours earlier, Russian strikes in the central Ukrainian city of Pavlograd set off a massive fire that lit up the night sky. Russian pro-war military bloggers, who closely follow the fighting, suggested that the strike targeted Ukrainian air defence systems, but did not offer evidence for the claim.

At least 34 people, including three children, were injured in the attack, according to Serhiy Lysak, the governor of the Dnipropetrovsk region, which includes Pavlograd. Dozens of buildings, including schools and homes, were damaged, he said. His office released photos of the aftermath that showed widespread wreckage.

Both sides have reported escalating attacks in recent days. Russia continued its bombardment of Ukrainian towns and villages along the front line over the weekend while a series of explosions also took place deep behind Russian lines.