A 14-day state of emergency has been declared in Papua New Guinea's capital, Port Moresby after more than a dozen people were killed in the country in rioting.

Prime Minister James Marape said 1000 military and police are also on standby to come into the capital from other parts of the country.

In a press conference surrounded by his government supporters, Marape also announced the suspension of Police Commissioner David Manning.

Marape said the deputy Police Commissioner of Operations Donald Yamasombi will be the acting commissioner for the duration of the state of emergency.

Other heads of department suspended include Finance Secretary Sam Penias, Treasury Secretary Andrew Oaeke and the Secretary for Department of Personnel Management, Taies Sansan.

"It's not good enough that operating agencies do not get to work properly that has caused us this stress," Marape said.

The violence broke out with shops and businesses being set alight late Wednesday (local time), after public servants, including police and army personnel, went on strike over a payroll issue.

Holistic review

Marape said the Chief Secretary of State as well as the Secretary of the Department of Justice would assemble a team of five to conduct a holistic review as to what happened on Wednesday.

He said the review would also leave room for criminal investigations into the conduct that took place.

"I want to inform the country that there is evidence of organised rioting that took place on Wednesday, where that organising came from is what the investigation will ascertain, whilst the police had a general cause of concern, there were organised people behind the scene, who were organising the rioting and that started the entire process and we will look into the organisation and where that support came from," he said.

Marape said the review will also look at police, treasury, finance, and personnel management.

"We want to ensure that this sort of thing does not happen again but more importantly, we secure democracy, we secure the rule of law, we secure good administration of respective public service organistaions including our discipline forces so that this sort of thing does not happen again.

"This is not the first time members of our discipline forces have gone rogue, we have incidents in the past where sporadic incidences of ill-discipline in our police force, in our defence force ... as well as public services."

"I want to indicate to our country, enough is enough."

Marape also had a message for members of the discipline forces.

"There are enough students in the country looking for jobs that can be trained to take your place if you step out of line, if you have sworn your loyalty then there are ways to deal with grievances. You don't go out and protest, that's not the way discipline forces behave."

Calls for him to step down

Marape, who is under increasing political pressure to step down, failed to mention in his media conference dissent within his government after six MPs resigned.

Six MPs have resigned from Papua New Guinea's government. They are Sir Puka Temu, David Arore, James Donald, Maso Hewabi, Keith Iduhu and James Nomane.

Chauve MP James Nomane and Hiri-Koiari MP Kieth Iduhu made their resignations public via social media.

Both blamed Marape for the riots in Port Moresby, which are now spreading to other parts of the country.

Nomane and Iduhu are members of Marape's ruling Pangu Party and have called on him to resign.

RNZ Pacific's Papua New Guinea correspondent, Scott Waide told Morning Report the riots in Port Moresby have taken a "hefty toll" on the government.

He said the MPs were disappointed in the way the Prime Minister handled the situation.

"They've expressed that he could have acted quickly and contained the situation and it took a long time before it all happened."

Waide said a few of the deaths occurred when shop owners "opened fire" on the looters and one or two were shot by police.

"The others sustained injuries with security personnel cutting them with machetes when they tried to attack the locations."

He said the riots have damaged economic confidence.

"Just look at the impact it's had on the number of shops that have been burnt, the economic confidence that it has affected, one of the biggest shopping centre franchises suffered enormous damage.

"Most of its shops were destroyed so it's affected the economy in a huge, huge way."

He said it was quiet yesterday with attempts to rob shops quickly stopped by police.

Violence spreads

Rioting has spread to other parts of Papua New Guinea.

Looting has been reported in the nation's second largest city Lae, as well as in the towns of Kokopo, Goroka, Madang, Bulolo and Kavienga.

Goroka has been badly affected with the Post Courier reporting widespread looting.

Law enforcement and the military have responded to the disorder.

Violence has not spread to Mt Hagen where tribal leaders, police and the military are on alert.

• RNZ