Voting in PNG's Southern Highlands and Hela provinces has been extended by a day with delays marring the start of the country's five-yearly elections.
Police spokesman Dominic Kakas says booths will be reopened on Sunday following reports throughout the region that many have be unable to vote after election commission staff and security were late arriving at some villages.
In Tari in Hela Province, residents have complained there are not enough ballot papers.
The electoral commission had planned to carry out one-day voting across the Highlands, which is home to more than half the country's estimated 4.6 million voters.
Police commissioner Tom Kulunga said during Saturday's visit to the region he would request an extension of voting.
In Tari, police fired five warning shots into the air above frustrated voters after a fight broke out at a booth.
"There are not enough ballots," one man told AAP.
"There are also lots of teenagers voting. It will be declared as a failed election." No one was injured in the incident.
The government of Peter O'Neill voted in early 2012 to delay the much anticipated poll by six months after Highlands MPs expressed concern over voter fraud.
However, the government backed down following public protests in the capital, Port Moresby.
The 2012 poll is PNG's eighth since gaining independence from Australia in 1975.
Competition in this election is fierce with much at stake, namely control of PNG's massive resources boom expected to come online over the next two years.
The O'Neill government was born in controversy when it ousted former prime minister and founding father Sir Michael Somare in August last year.
Sir Michael is running again in the seat of East Sepik which he has held for 44 years.
However, he has told local media he will only stay in parliament long enough to see a new government formed under his National Alliance party.
Mr O'Neill and his deputy Belden Namah accuse Sir Michael of squandering opportunities to build PNG's ailing infrastructure during his recent nine-year stint in the top job.