A man has described the frantic phone call he received from his asylum seeker brother, who was left "covered with blood" after violence erupted at the Manus Island detention centre overnight.

A second riot at the centre in Papua New Guinea last night left one asylum seeker dead, another in a critical condition and 13 others with serious injuries.

Ghulam Murtaza, who fled Pakistan and is in Australia on a bridging visa, has told the ABC his brother Ghulam Mustafa rang him about 11:40 last night.

He says his brother told him police and locals were trying to force the asylum seekers from the detention centre.

"He was crying and he was shouting. He said, 'the local people of Manus Island and police are fighting with us'," he said.

"[He said], 'the local peoples on Manus Island are throwing stones on us. They have guns ... and they have sticks and they are going to kill us'."

Mr Murtaza said his brother urged him to get a message to the media to "help us ... or we will all die".

"My brother said, 'I am also injured. I am covered with my blood. Someone hurt me by stones and sticks. I don't know when I will talk to you again'," he said.

Mr Murtaza says his brother told him the violence erupted after asylum seekers were told they would be in PNG for at least 10 years.

He says he was told authorities cut power to the detention centre and that asylum seekers from three compounds had escaped.

By the time his brother called him, just five or six people were left in his compound.

Brother had been urged not to come by boat

Mr Murtaza arrived in Australia in July last year.

His brother arrived shortly afterwards and was among the first group to be sent to Manus Island on July 20.

"When I reached Christmas Island I said to my brother, please do not come here by boat. If you want to come here, come here by plane," he said.

"But he never listened to me and today he is in Manus Island.

"In our country we are not secure. In Papua New Guinea we are not secure."

Mr Murtaza has not had contact with his brother since. He does not know how to get back into contact with him.

He says his brother has always contacted him from a private number within the centre.

Asylum seekers also called refugee advocates

Refugee advocates say the outbreak of violence prompted distressed asylum seekers to call them for help.

The Asylum Seeker Resource Centre recorded some of the calls it has received.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Listen Duration: 3 minutes 1 second 3 m 1 s Asylum seeker calls Asylum Seeker Resource Centre from Manus Island Download 1.4 MB

They cannot verify the identity of the callers, but say the details are consistent with other information they have received.

One caller said asylum seekers feared both security staff and local residents.

"They are still killing. I do not know until now if they killed many of us or they injured one of us. But everyone is bleeding," the caller said.

Morrison promises inquiry into unrest

Immigration Minister Scott Morrison said it was his "great regret" to report the extent of the injuries sustained by asylum seekers in the riot.

He has promised a full inquiry into the "very tense and very stressful" incident.

"The deceased person involved a head injury and that person passed away on transfer to the hospital," he said.

Mr Morrison said the person was injured outside the centre.

The asylum seeker who is listed as critically injured received a skull fracture and one seriously injured asylum seeker was shot in the buttock.

Sorry, this video has expired Watch vision of Sunday night's disturbance

Both are being transferred to Australia for treatment.

The latest incident follows unrest on Sunday night when 35 asylum seekers escaped from the detention centre but were recaptured.

The ABC has obtained video footage of that incident, shot from the perimeter of the compound.

It shows detainees shouting and throwing stones at guards and houses nearby.

The detainees are also seen rushing towards the main gate.