Greenpeace activists have re-occupied an oil rig in the Cromarty Firth, just hours after police moved in to end the protest.
A police operation on Thursday saw two men arrested on the Transocean rig, which is on contract to BP.
But Greenpeace said two more climbers later boarded the rig, which was due to be towed to the Vorlich oil field east of Aberdeen.
Nine people have been arrested since the protest began on Sunday evening.
Greenpeace UK’s executive director John Sauven said: “Our climbers are back on the oil rig and determined to stay for as long as possible.
“BP are heading out to drill a new well giving them access to 30 million barrels of oil – something we can’t afford in the middle of a climate emergency.
“We can’t give up and let oil giants carry on with business as usual because that means giving up on a habitable planet and our kids’ future. The UK government has announced a target of net zero greenhouse emissions by 2050 – we have started to enforce it.”
A helicopter and boats were used by police to try to end the occupation on Thursday after the rig’s owner Transocean obtained an interdict to remove the activists.
Police Scotland said it assembled a specialist team of officers from across the country to carry out the “extremely complex and challenging operation”.
Greenpeace said officers in climbing gear removed a protest banner, while the rig itself was lowered into the water to allow two police boats to access the gantry where the activists were camped out.
Two men, aged 40 and 50, were arrested.
Responding to the latest developments, BP said the occupation was “reckless” and that it was working with Transocean and Police Scotland to bring it to a safe conclusion.
A spokesperson said: “BP supports debate, discussion and peaceful demonstration, but the irresponsible actions of this group are putting themselves and others unnecessarily at risk, while ignoring court orders and police action.”