Three teenagers have appeared before the Waigani Committal Court, charged over the killing of four Chinese nationals in Port Moresby last month.
One of the teenager is from Northern province, while the other two are from Gulf.
The four Chinese nationals included a couple, who operate the Poomo Industry (PNG) Limited, and two others who work in the store at Koki.
Two of the suspects were arrested over the weekend following a police operation in Gulf province, while the first was arrested in the capital city.
National Capital District and Central Police Commander Jim Andrews told NBC News, while the three have admitted to committing the crime, a motive is yet to be established.
"The first one that was arrested last week is, his name was John Makai, male, aged 18 years, from Korara village of Sapea district of Oro province.
"He was the inside man in the shop that organise these attacks.
"The other two were Keith Lasi Ahira is a male age 19 of Kaivu-Koru village, Ihu District, he is one of those executors, using bushknife.
"The other Eric Naks Lako, male, age 18 of same village from the same province, he is also the executor using a bushknife to chop those Chinese," Commander Andrews said.