Ukraine is on guard against the possibility of more Russian attacks on infrastructure, with people feeling the impact of such strikes carried out so far.

Ukraine's military warned on Sunday that there was still a threat of Russian forces launching missile strikes on critical infrastructure. A senior ruling party lawmaker also wrote on social media that the coming week could be really difficult.

Efforts are underway to restore power plants and other facilities damaged by Russian attacks. But Ukraine's state-run utility firm called on people to cut power use as electricity production was about 20 percent short of consumption needs.

Kyiv Mayor Vitali Klitschko posted a video on social media that had been filmed while snow was falling. It shows him emphasizing that he was seeking to restore heating and other facilities to minimize the impact of Russian attacks on people's lives.

Meanwhile, Russian forces mounted attacks on Sunday. Governor Pavlo Kyrylenko of Ukraine's eastern region of Donetsk says shelling in a central town left two people dead and another wounded. The governor argued on social media that Russia was consistently and deliberately targeting civilians.

The UK defense ministry said on Sunday that the area around the towns of Pavlivka and Vuhledar in south-central Donetsk "has been the scene of intense combat over the last two weeks."

It said both Moscow and Kyiv "have significant forces committed" to the fighting, with Russia's naval infantry "having suffered heavy casualties."

The ministry said "Russia assesses the area has potential as a launch point for a future major advance north to capture the remainder of" Ukrainian-held territory in Donetsk.

But the ministry said "Russia is unlikely to be able to concentrate sufficient quality forces to achieve an operational breakthrough."