Russian troops advancing to the Ukrainian capital of Kyiv and other major cities are believed to be facing fierce counterattacks from Ukrainian forces.

Media outlets are reporting that an apartment building in Bucha, about 20 kilometers northwest of central Kyiv, came under attack.

The media are also reporting that Russian tanks have entered Bucha and sporadic shooting is taking place.

In the second largest city of Kharkiv, Russian tanks are said to be advancing into the center.

The governor of the province that includes Kharkiv posted a message on Facebook, urging residents to stay in shelters.

Russian troops are attacking key infrastructure facilities.

A Ukrainian government agency says Russian forces fired a missile into a radioactive waste storage facility in Kyiv early Sunday morning, local time.

Ukrainian media say the missile did not hit the facility. Government officials say the incident will not have any impact on residents.

Russian presidential spokesperson Dmitry Peskov said on Sunday that the government sent a delegation to the Belarusian city of Gomel for talks with the Ukrainian side.

Ukrainian President Volodymyr Zelenskyy posted a message on social media, indicating that he would reject negotiations in Belarus because the country is playing a role in Russia's aggression.

But he expressed hope to hold talks to end the fighting, proposing Poland, Turkey and some other countries as alternative venues.