The rioting has caused a political crisis in the country and calls for Mr Marape to resign. Critics accused him of being weak and mishandling the situation.
Six MPs have quit his government over the unrest.
‘Crisis happening under your watch’
One of them, James Nomane, accused the prime minister of turning Papua New Guinea into a “banana republic”.
“Resign for being indecisive and weak. Resign for the country slipping into a banana republic and for this crisis happening under your watch,” he said.
Keith Iduhu, another MP, said Mr Marape had failed to address the grievances of soldiers and police officers.
‘Bureaucratic negligence’
“The core issue surrounding the grievances raised by the disciplinary forces was completely avoidable had it not been for bureaucratic negligence,” he said.
Papua New Guinea has been plagued for decades by poverty, tribal tensions, poor governance and crime.
Those problems have been exacerbated by inflation and rising living costs.
About 40 per cent of Papua New Guinea’s nine million citizens live below the poverty line despite its natural resources, including gold and timber.
Port Moresby is routinely listed as one of the world’s least liveable cities, along with the likes of Lagos, Karachi and Tripoli.
Located 125 miles from Australia’s northernmost border, Papua New Guinea is the largest and most populous state in Melanesia.
Australia recently signed a security deal with the country, promising to help its stretched police force combat arms trafficking, drug smuggling and tribal violence.
“We continue to urge calm at this difficult time,” Anthony Albanese, the Australian prime minister, said on Thursday.