Papua New Guinea police opened fire on students rallying in the capital, Port Moresby, as they prepared to march to parliament on Wednesday.

The protesters were calling for the removal of Prime Minister Peter O'Neill, who is accused of corruption and mismanagement. The demonstration was believed to be timed to coincide with a vote of confidence against O'Neill.

"They fired shots, they fired shots directly at the crowd," student Gerald Peni told the Australian broadcaster ABC, which reported that four people had been killed in the gunfire.

"Many of the students they fell, they got injured, we don't know how many casualties we may have at the moment."

Papua New Guinean broadcaster EMTV tweeted that several people had been injured, and were being treated at Port Moresby General Hospital.

EMTV said instances of unrest had been happening around Port Moresby since the failed protest march. Outside the hospital itself, further gunfire was reported.

Amid reports that some of those who had been shot had died, Australia's Foreign Minister Julie Bishop said Canberra was still trying to ascertain what had happened.

"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," said Bishop.

Formerly administered by Australia, Papua New Guinea suffers from endemic violence, poverty and high levels of serious crime.

(DW)