A total of 170 people, including children, have been arrested in Newcastle for allegedly defying directions by New South Wales Police during an anti-fossil fuel protest at the world's largest coal port.
Dozens of protesters on kayaks and small water craft paddled out on Newcastle Harbour on Sunday morning.
Standing on the beach, a police officer using a loud speaker told those gathered on the sand they could be breaking the law if they entered the shipping channel.
NSW Police said just after 10am on Sunday a large group of people entered the shipping channel and interfered with the movement of vessels.
As a result police said 170 people had been arrested over unsafe behaviour in the water, serious disruption of a major facility and other offences.
Of those arrested, 156 were adults and 14 were children.
Thousands of people have gathered in Newcastle over the past few days for what activism group Rising Tide has called "the people's blockade" of the world's largest coal port.
The police operation on the harbour is continuing and police aren't ruling out further arrests.
"NSW Police will adopt a zero-tolerance approach to actions which threaten public safety and the safe passage of vessels," a statement said.
Ten people also needed assistance from officers to return to shore, police said.
Police disappointed infant seen on kayak
Assistant Commissioner David Waddell, Commander of the Northern Region, says police were disappointed by the safety risks taken by some protesters.
"We had 34 people who were required to be pulled out of the water by the Police Marine Area Command or divers," he said.
"We had 10 people that required assistance back to shore by Water Police because they couldn't get back to shore themselves.
"And we had one infant around 12 months old that was sighted in a kayak out on the water."
Shipping movements paused
Rising Tide has declared the protest action successful, claiming the paddle-out forced a bulk carrier to turn around and not enter the port.
The Port Authority has confirmed shipping movements in and out of the Port of Newcastle were temporarily paused.
"In consultation with NSW Police and stakeholders a risk-based decision has been made to temporarily pause shipping," a spokesperson said in a statement.
"The protest activity has compromised the safety of the shipping channel and led to an unacceptable potential risk to public safety, the port and the environment."
After being on hold for several hours shipping movements have now resumed.
Former footballer joins protest
Former Socceroos player Craig Foster was one of dozens of people to paddle out onto the harbour.
He said he felt it was time he joined the action rather than just sitting back and watching.
"We need to take more action on climate [change] … we need more leadership.
"I've been watching many climate protests all around the world … and it's becoming more and more important that society, that all of us, just step forward.
"We shouldn't expect others to do things that we won't do ourselves."
NSW shadow minister for police Paul Toole has labelled the protesters "numbskulls".
"Rising Tide are repeat offenders of creating anarchy in our ports, disrupting the daily lives of Australians and conducting themselves in an illegal and unacceptable manner," he said.
"These protesters are just complete numbskulls trying to manipulate their way around our laws.
"They are intent on causing the most disruption for the fewest prosecutions, and it's about time they are properly fined and given imprisonment terms for their behaviour."