Russia’s military forces have kept up their punishing campaign to capture Ukraine’s capital with fighting and artillery fire in Kyiv’s suburbs, even as Russian and Ukrainian negotiators held a new round of talks on Monday.

The attacks around Kyiv came a day after Russia escalated its offensive by shelling areas close to the Polish border.

In the eastern city of Kharkiv, firefighters doused the remains of a four-storey residential building on a street of apartments and shops. Ukrainian emergency services said a strike hit the building, leaving smouldering piles of wood and metal. It was unclear whether there were casualties.

The surrounded southern city of Mariupol, where the war has produced some of the greatest human suffering, remained cut off despite earlier talks on creating aid or evacuation convoys.

A pregnant woman and her baby died in Mariupol after Russia bombed the maternity hospital where she was meant to give birth.

Russia’s invasion, launched on February 24, has forced nearly 2.8 million people to flee Ukraine. Thousands of civilians and soldiers have been killed.