Oslo - Over 150 crew were evacuated from a Norwegian oil rig after oil leaking into the North Sea presented the risk of an explosion, authorities said Saturday.

A core team of some 60 workers remained on the Statfjord A platform in Norwegian waters to repair the leak, said a spokesman for StatoilHydro, the platform's operators.

The spokesman described the situation as "severe". The dawn evacuation was carried out by helicopters, with crew taken to nearby rigs.

The alarm was given when inspectors discovered gas escaping from one of the rig's supply shafts. StatoilHydro operates three rigs in the Statfjord field, which produces
150,000 barrels of oil a day. (dpa)