Production was being rebooted on Thursday from a number of North Sea fields that were shut in off Norway due to the temporary closure by Equinor of the Sture onshore terminal after a collision between two ships near the facility early the same day.

Both the Sture terminal and Kollsnes gas processing plant on Norway’s west coast, which was also shut down, had resumed operations, while installations affected by the closures were gradually starting up again, Equinor said in a statement.

Production had earlier been halted at the Aker BP-operated Ivar Aasen field and Lundin Petroleum’s Edvard Grieg field, as well as Equinor’s Troll A, Oseberg and Grane fields.

The collision occurred around 4am when oil tanker TS Sola that was departing the terminal collided with Navy frigate Helge Ingstad, which had lost control after a steering failure and was drifting towards land with 137 personnel onboard.

A tugboat, Tenax, was also involved in the incident, according to the Accident Investigation Board Norway.

The frigate’s crew was evacuated and the vessel, which was in danger of sinking, was in the process of being salvaged, Norwegian state news channel NRK reported.

There were 23 people onboard the tanker - laden with 600,000 barrels of oil - at the time of the collision but these were unharmed, although eight others suffered minor injuries, a spokesman for the country’s offshore emergency centre was quoted as saying.

There has also been a reported leak of 10,000 litres of helicopter fuel into the sea outside the terminal.

Equinor had shut down the export terminal and evacuated all personnel without emergency tasks as a precautionary measure.

A spokeswoman for the state-controlled operator told NRK it would still be able to meet its crude supply commitments despite the closure of the terminal.

Gas system operator Gassco said in a statement it was “working to minimise the consequences for companies exporting Norwegian gas and European recipients" after the Kollsnes shutdown.

“The company optimises gas transport by exploiting the flexibility in the integrated network," it stated.

The plant, with a processing capacity of 144.5 million cubic metres per day, processes gas from the Troll, Kvitebjorn and Visund fields and sends it to the UK and the rest of Europe.

The Sture terminal receives oil via pipelines from a string of North Sea fields, including Oseberg, Grane, Svalin, Edvard Grieg and Ivar Aasen, which in turn is exported to global markets on oil tankers.

Oslo-based research firm Rystad Energy had estimated the terminal closure would have hit about 365,000 barrels per day of oil production from offshore fields.