A fleet of kayaks blocked shipping traffic over the weekend at the Port of Newcastle on Australia’s east coast, imploring the government to end the country’s long reliance on fossil fuel exports.

Authorities agreed to let the protest run for 30 hours, but police boats started closing in when the deadline expired and crowds of activists refused to leave the water.

Among the 109 people arrested was 97-year-old Uniting Church reverend Alan Stuart, who said he wanted to stave off climate disasters for his “grandchildren and future generations”.

“We chose to risk arrest because scientists are warning that to avoid catastrophic climate collapse we must urgently phase out fossil fuels,” said the protest group Rising Tide, which organised the blockade.

New South Wales Police said five juveniles had also been arrested but did not give their ages.

A succession of Australian states have passed strict laws in recent years targeting climate protests, drawing condemnation from civil rights organisations and United Nations investigators.

Climate protester Deanna Coco was jailed for 15 months late last year after blocking traffic on Sydney’s famed harbour bridge, although her sentence was later quashed on appeal.

Australia has long been one of the world’s largest coal producers and a string of new coal mines, oil fields, and gas projects are currently in government planning pipelines.