About 60 asylum seekers and guards came to blows in the running battle, as the governments of PNG and Australia met in Port Moresby to discuss refugee resettlement.
The riot, sparked by poor food quality, followed another fight last month when barriers were erected around kitchens, slowing the serving of meals.
A refugee from Iran, Amir Taghinia, said tension had been building in the centre as asylum seekers denied refugee status were repatriated and in some cases forcibly deported.
"Many people are saying it's about food and it's because of the quality of the food. Yes, the quality of the food is not good. Food distribution is not happening in a proper way, but the main thing is there is not a good atmosphere in the west area," said Mr Taghinia.
"They are forcibly deporting people after four years and there are many people that possibly cannot go back to their homes. They are saying, if we could we would have gone back home years ago. There's a very negative atmosphere in here."
As refugees and guards exchanged volleys of rocks and water bottles, the governments of PNG and Australia met in Port Moresby.
On the table was the plan to resettle refugees in the United States of America, for which only 300 of about 600 eligible detainees were identified last week by the US Department of Homeland Security.
A refugee from Pakistan, Naseem Heidar, said it was clear to the detainees they would not all be going to America.
"If in these 300 people if someone is reject by Homeland Security, what will be happen with them? Does the government have any plan for them?" asked Mr Heidar.
"What will happen with those guys who are a positive (refugee status) but still living in Manus Island and they didn't have any interview with America?"
The PNG Foreign Minister Rimbink Pato said other countries might be sought to resettle the Manus men if America did not take them all.
"Should they not resettle them then obviously that's a challenge that Australia and Papua New Guinea will work together to resolve, in terms of either resettling them in PNG or those that have to be resettled in a third country," said Mr Pato.
But no other third country resettlement options were put forward following the Port Moresby meeting, a fact not missed by Mr Taghinia.
"Australian government is saying they are not in talks with any other countries to resettle people," he said.
"And there is always talk in the centre from the case managers, from the case workers, from the officers and many other people that, you're not going to go to America, this is not going to happen. This is just a game to keep you quiet for a while. The uncertainty in here is the most important thing that people are very angry about."
Mr Heidar was equally sceptical about the deal with the US.
"So when they are decide to sending people to the USA to resettle them, why is it taking so long time?" he asked.
"Why it's not coming in the action? Because I never believed the America deal will become real. If it's come in the real they can't take all the people."
Twenty-six of the refugees have so far been settled in PNG, but violent conflict with local people on Manus Island had deterred others from wanting to stay.
The detention centre is due to close at the end of October.
Kurdish Journalist Behrouz Boochani contributed to this story.