Environmental campaigners who scaled a chimney at a coal-fired power station in Britain in protest at the pollution it creates ended their demonstration voluntarily on Wednesday, police said.

Nine people came down from the chimney at the Didcot Power Station in Oxfordshire, southeast England, and were arrested, police said. At least a further 10 people were arrested when the protest began on Monday.

- The protesters, four women and five men, who had climbed to the top of the emissions chimney, came down at around 4:30 am and were subsequently arrested - on suspicion of aggravated trespass, Thames Valley police said.

A spokeswoman for RWE power, a unit of German energy company RWE Group which operates the power station, said they were "relieved" at the outcome. They had shut down the coal conveyor on Monday for safety reasons.

Climate change protesters earlier this month targeted one of Britain's biggest coal-fired power stations, near Nottingham, central England, owned by German energy giant E.ON.