Papua New Guinea`s prime minister declared a 14-day state of emergency in the capital on Thursday, after 15 people were killed in riots as crowds looted and burned shops.
Violence erupted in Port Moresby on Wednesday evening after a group of soldiers, police officers and prison guards launched protests over unexplained deductions to their pay.
Within hours the unrest had also spread to the city of Lae, about 300 kilometres (186 miles) to the north of the capital.
"Today we call for a state of emergency for 14 days in our nation`s capital," Prime Minister James Marape announced.
More than 1,000 troops were on standby "to contain any situations that may arise going forward", he said.
At least 15 people were killed in the unrest in Port Moresby and Lae, said Police Commissioner David Manning.
Port Moresby`s largest hospital treated 25 people with gunshot wounds, according to figures provided to AFP, as well as six people with "bush knife" lacerations.
AFPTV footage showed looters in the capital dashing into stores through smashed glass windows, stuffing stolen goods into cardboard boxes, shopping trolleys and plastic buckets.
One man was seen lugging an entire chest freezer away on his shoulders.
Buildings and cars were set alight, AFPTV footage showed, stirring up thick plumes of black smoke that hung over the worst-hit parts of the city.
The US Embassy in Port Moresby said shots were fired near its compound as police tried to "disperse groups of looters".
A smaller crowd gathered earlier outside the prime minister`s office in Port Moresby, tearing a security gate off its rails and torching a parked police car.
Beijing has lodged a complaint with Papua New Guinea`s government, following reports that rioters targeted Chinese-owned businesses.
Its foreign ministry said two Chinese nationals had been "lightly injured" in the violence.
"We remind Chinese nationals in PNG to pay close attention to the changing security situation on the ground," ministry spokesperson Mao Ning said on Thursday.
`End this strife`
Port Moresby resident Maho Laveil, an economics lecturer at the University of Papua New Guinea, said peace had "largely been restored" by Thursday evening.
"They`ve chased the looters away, they`ve stopped the buildings from burning," he told AFP.
National Capital District governor Powes Parkop said the unrest represented an "unprecedented level of strife" in Port Moresby, while local newspaper the Post Courier called it the city`s "darkest day".
"What is most important is that we must end this strife," Parkop told a local radio station Wednesday evening.
"Nobody will be a winner in this type of civil unrest."
Security forces staged a protest inside Papua New Guinea`s parliament after noticing their pay had been docked.
Although the government swiftly promised to fix what it described as a payroll "glitch", it was not enough to stop disgruntled civilians from joining the fray.
The prime minister said four department chiefs involved in the payroll problem -- the heads of personnel, finance and treasury as well as Police Commissioner David Manning -- had all been suspended for 14 days.
The burst of violence highlights the often volatile nature of life in Papua New Guinea, a country plagued by poverty and high levels of crime.
Less than 200 kilometres from Australia`s northernmost border, Papua New Guinea is the largest and most populous state in Melanesia.
Although it is blessed with vast deposits of gas, gold and minerals, human rights groups estimate that almost 40 percent of its nine million citizens still live below the poverty line.
Australia recently signed a security deal with Papua New Guinea, promising to help its stretched police force combat arms trafficking, drug smuggling and tribal violence.
"We continue to urge calm at this difficult time," Australian Prime Minister Anthony Albanese told reporters on Thursday.
