At 15 p.m. on Sunday, some parts of Uppsala – including Vattenfall's own heating plant in Boländerna – were affected by a power outage.

In households, electricity soon returned, but the heating plant is still without power – which has consequences.

"I don't know what happened. This affects 90 per cent of Uppsala's population," says Johan Sennerö, press contact at Vattenfall.

At 17 p.m., service technicians were on their way to the heating plant, but we have no forecast for how long it will take. And once we get the plant up and running, it will take hours for it to have an effect," says Johan Sennerö.

"So it can get cold in the cabins tonight.

The text will be updated.