Australia's Foreign Minister Julie Bishop says police have shot students protesting against Papua New Guinea's prime minister in the South Pacific nation's capital of Port Moresby.

Bishop says she had been advised by Australia's embassy in Port Moresby of the violence on Wednesday morning as the students prepared to march from the university to Parliament.

She told reporters: "I know that students have been shot, but we're still trying to determine whether there have been deaths and how many have been injured."

Australian Broadcasting Corp. reported a lawmaker told Parliament that four students had been killed and seven wounded.

Police spokesman Domonic Kakas says he can't comment.