MELBOURNE (Reuters) - Protesters rallied in Australia’s two largest cities, Sydney and Melbourne, on Saturday calling for an end to the country’s controversial South Pacific detention centers which house refugees who try to reach Australia by boat.

Particular focus was directed toward the wellbeing of children on the tiny island nation of Nauru, though refugee advocates said all refugees should be out of detention.

“It’s kids off, everyone off and bring them here,” Ian Rintoul, from the Refugee Action Coalition told Reuters on Saturday.

More than 1,400 people are being held on the Australian-run detention centers on Nauru and Papua New Guinea, some for years.

The rally organizers said thousands attended the protests in each city, but local media had smaller estimates. There was no estimate from police.

Australia refuses to allow asylum seekers arriving by boat to reach the country. It says the policy deters people smugglers in Asia from plying their trade and saves lives by stopping people sailing in unseaworthy boats from Indonesia to Australia.

Australian Prime Minister Scott Morrison is under increased pressure to immediately resettle children on Nauru, after aid agencies and doctors raising concerns of a health crisis.

Worsening mental health has left some of the children on Nauru in a “semi-comatose state”, unable to eat, drink or talk, says humanitarian group Médecins Sans Frontières (MSF), which was ejected from Nauru by the island’s government.

Morrison’s government is on the verge of losing its majority after a devastating by-election on October 20, and key independents have warned their support hinges on him freeing children on Nauru.

On Monday, 11 child migrants were evacuated from Nauru for medical treatment.

Australia first introduced offshore processing of refugees between 2001 and 2008 and started it again in 2012. In 2013 it significantly toughened the policy, ruling that even if people were found to be refugees they would never be resettled in Australia.