Ten arrested as activists scale Sydney Harbour Bridge over 'climate emergency'

Greenpeace Australia is leading a protest action on the Sydney Harbour Bridge to demand the major political parties do more to deal with climate change.

Environment activists have abseiled down the Sydney Harbour Bridge to demand that Prime Minister Scott Morrison declares a climate emergency. Source: Greenpeace

Police have arrested 10 people after a group of environmental activists abseiled off the Sydney Harbour Bridge to demand the major federal political parties declare a "climate emergency".

About 5.15am on Tuesday, Harbour Bridge security staff spotted several people on the bridge.

They detained some while waiting for police to arrive, but part of the group climbed under the bridge and begun abseiling, a NSW Police Force spokesperson said.

A Greenpeace protester tries to roll out his sign as he hangs from the bridge. Source: Seven Network

Police are still trying to remove three protesters, who are attached to ropes beneath the bridge. 

"Australia is facing a climate emergency right now," Greenpeace Australia Pacific CEO David Ritter said in a statement on Tuesday.

"We're here today to say 'no more'."

The Greenpeace supporters unfurled banners calling for action as they abseiled from positions underneath a public walkway on the western side of the bridge.

Roads and Maritime said one lane of the bridge was closed earlier, during the police operation.

Motorists are no longer expected to face delays on the bridge.