More on reports that the global demand for energy is set to plummet by a record amount this year, according to a forecast from the International Energy Agency (IEA).

The group has warned that storage space for excess crude oil is likely to run out in the coming weeks.

"We may well see around mid-June the global storage capacity [will] be full," executive director Fatih Birol told Reuters news agency. He said the problem was worst in North America.

Oil firms have resorted to renting tankers to store the surplus supply and that forced the price of US oil into negative territory for the first time in history earlier this month.

But prices have begun to rebound since then.