An Australian college professor was one of several people taken hostage by armed criminals in the highlands of Papua New Guinea, the country’s prime minister said Monday. The unnamed academic is among a group of captives which includes several foreign citizens, police said, with the hostage-takers demanding a cash ransom for their victims’ release. Sources told Reuters that the professor works for an Australian college and was on a field trip to Fogoma’iu village in the Mount Bosavi region when they were captured along with local researchers and a project manager. “We want those criminals to release those who are held in captivity,” Papua New Guinea Prime Minister James Marape said on Monday, adding that police and the military have been put on notice over the incident.