A senior Ukrainian energy official has warned that scheduled power outages and emergency blackouts will intensify over the coming weeks, after a wave of Russian attacks crippled Ukrainian electricity generation.

“Over the next few weeks, the situation will be much tougher than it is today,” the head of national grid operator Ukrenergo, Volodymyr Kydrytsky, said in an interview broadcast on state media on Sunday evening.

He said periods during which Ukrainians might not have power were likely to be extended by up to 12 hours a day and that outages could become more “stringent”.

“This situation will continue until the end of July,” Kydrytsky said, adding that scheduled outages could also be imposed during peak consumption periods and be “quite serious”.

Russia renewed a campaign of aerial attackson Ukrainian energy facilities in March, which Kyiv says has knocked out half of its power generating capacity and forced Ukraine to introduce rolling blackouts in the capital and across the country.

Lengthy summer power cuts, as well as domestic price increases, are already afflicting Ukraine, with state agencies forced to cut energy use, adding urgency to the calls to boost air defences.