Papua New Guinea's Prime Minister Peter O'Neill has dismissed Australian concerns after police in Port Moresby opened fire on a crowd of student protesters earlier this week.
Mr O'Neill expressed sympathy to those who were wounded, but refused to change his position on the students' concerns.
"This confrontation was unnecessary," he said.
"It could have been handled a bit better, by ofcourse not allowing this sort of confrontation to take place."
The violence came after weeks of protests demanding Mr O'Neill resign over corruption allegations.
At least 17 people were wounded, prompting Australian Prime Minister Malcolm Turnbull to offer support.
It was immediately rejected.
"These are internal matters for Papua New Guinea," Mr O'Neill said.
"Papua New Guinea can handle these matters. We've been an independent country for 40 years."
More unrest as multiple inquiries announced
Central PNG towns like Wabag and Kundiawa have staged protests in solidarity with the students, demanding Mr O'Neill resign.
Anger has also spread to PNG's volatile highlands region, with students reportedly carrying out surprise attacks on government buildings, including a courthouse in Mount Hagen.
At least three investigations into the Port Moresby shooting have been ordered.
Authorities have promised to investigate the conduct of police, students and other organisations, including any that may have backed the protesters financially.
Most of the investigations will require approval from the government, which has suspended parliament until August.
The government remained confident PNG University classes will resume next week, but student leaders have said they will consider a mass withdrawal from universities across the country.
Students at Papua New Guinea's University of Technology in Lae have condemned the government's actions.
"The MPs, they are not representing the interests of the people," said David Kelma from the Unitech Student Representative Council.
"When the people are suffering and going through this, they should speak up."
With the University of PNG also facing investigation, its Acting Chancellor Nicholas Mann refused to comment on how police reacted.
"What we did, we did in the best interests of the students," he said.
"That's all I can say.
"I know where you're coming from, you want to say 'the university condemns the police'. No. Whatever they did, good or bad, it's up to police to explain."
Lawrence Stevens from human rights group Transparency International has been more vocal, labeling the reports "shocking".
"I would hope they would cease putting weapons in the hands of people who are supposedly doing civil duties," he said.
"You can't have high-powered weapons being carried around like biros (pen)."