Russia attacked the Ukrainian capital in the early hours of Sunday morning, striking at least two residential buildings, Kyiv Mayor Vitali Klitschko said, as elsewhere Russian troops consolidated their gains in the east.

Associated Press journalists in Kyiv saw rescue services battling flames and rescuing civilians. Klitschko said two people were hospitalised with injuries and a 7-year-old girl was pulled alive from the rubble.

Ukraine Member of Parliament Oleksiy Goncharenko wrote on the Telegram messaging app that “according to prelim data 14 missiles were launched against Kyiv region and Kyiv.”

Before Sunday's early morning attack, Kyiv had not faced any such Russian airstrikes since June 5.

Meanwhile, Russian forces have been seeking to swallow up the last remaining Ukrainian stronghold in the eastern Luhansk region, pressing their momentum after taking full control Saturday of the charred ruins of Sievierodonetsk and the chemical plant where hundreds of Ukrainian troops and civilians had been holed up.

Serhiy Haidai, governor of the Luhansk region that includes Sievierodonetsk, said Sunday that Russia was conducting intense airstrikes on the adjacent city of Lysychansk, destroying its television tower and seriously damaging a road bridge.

“There's very much destruction — Lysychansk is almost unrecognisable,” he wrote on Facebook. On Saturday, Russia also launched dozens of missiles on several areas across the country far from the heart of the eastern battles.

Some of the missiles were fired from Russian long-range Tu-22 bombers deployed from Belarus for the first time, Ukraine's air command said.

The bombardment preceded a meeting between Russian President Vladimir Putin and Belarusian President Alexander Lukashenko, during which Putin announced that Russia planned to supply Belarus with the Iskander-M missile system.

Russian Defense Ministry spokesman Igor Konashenkov said late Saturday that Russian and Moscow-backed separatist forces now control Sievierodonetsk and the villages surrounding it.

He said the attempt by Ukrainian forces to turn the Azot plant into a “stubborn centre of resistance” had been thwarted.

Haidai confirmed Saturday that Sievierodonetsk had fallen to Russian and separatist fighters, who he said were now trying to blockade Lysychansk from the south.

Russia's Interfax news agency quoted a spokesman for the separatist forces, Andrei Marochko, as saying Russian troops and separatist fighters had entered Lysychansk and that fighting was taking place in the heart of the city.

There was no immediate comment on the claim from the Ukrainian side.

Lysychansk and Sievierodonetsk have been the focal point of a Russian offensive aimed at capturing all of the Donbas and destroying the Ukrainian military defending it — the most capable and battle-hardened segment of the country's armed forces.

Capturing Lysychansk would give Russian forces control of every major settlement in the province, a significant step toward Russia's aim of capturing the entire Donbas.

The Russians and separatists control about half of Donetsk, the second province in the Donbas.