Papua New Guinea's prime minister, Peter O'Neill, has condemned Monday's killing of four Chinese people in Port Moresby.
According to the police, the victims, who are believed to be members of the same family, were stabbed to death.
Police are not ruling out the possibility of the suspects being family or very close to those that were murdered.
Mr O'Neill says he wants to assure the government of China and relatives of those killed that police will get all the help necessary to track down and bring the perpetrators to justice.
In Beijing, a foreign ministry spokeswoman said China's ambassador to Papua New Guinea has demanded swift justice and urged PNG to take robust measures to ensure the safety of Chinese nationals and property.
The PNG government recently proposed several tough new anti-crime measures in response to a surge in high-profile violent crimes.