Flight restrictions affecting Helicopter flights to offshore oil platforms in the UK and Norwegian sectors of the North Sea have been mostly lifted.

Most UK-based helicopter services, which shuttle workers between the mainland and offshore oil and gas platforms, have resumed flights to parts of the central and northern UK North Sea.

The southern part of North Sea, however, remains grounded following fears of volcanic ash in air space.

Helicopter flights transporting staff to and from Norwegian rigs have taken place.

Aberdeen Airport spokesperson Sarah Campbell confirmed that helicopter flights were being made from the Scottish airport, which transports more than 500,000 passengers a year for the oil and gas industry, reports Dow Jones.

Ash from the Eyjafjallajokull volcano has drifted over much of northern Europe resulting in the grounding of aircraft on the advice of airline safety group NATS.

The airspace over northwest Scotland, however, continues to be affected by a dense concentration of volcanic ash.

Statoil, the largest operator of offshore platforms in the region, said production has not been affected by the new flight suspension.

BP, which operates offshore platforms in the UK, also said its oil and gas production had not been affected by the grounding of helicopters.