At least 10 people were injured Wednesday in Papua New Guinea when police opened fire on university students protesting against the government, officials and local media said.
Earlier, Australian broadcaster ABC had said four people were killed, but the prime minister's office denied that any protesters died, and the police department and Port Moresby General Hospital said they had not received any reports of fatalities.
The shooting took place as the students attempted to march from the university towards the parliament in the capital Port Moresby to demand the resignation of Prime Minister Peter O'Neill.
The students told ABC that police had fired shots directly into the crowd and had punched and kicked protesters.
For the past five weeks, the students have been protesting against the prime minister's handling of corruption allegations.
Video clips purported to be from the rally shared on social media showed shots being fired by the police, followed by plumes of white smoke.
Activists and students say the prime minister has refused to comply with a two-year-old warrant for his arrest over a corruption inquiry following his alleged payment of about 30 million Australian dollars (22 million US dollars) in fraudulent legal bills to a law firm.
O'Neill released a statement on Wednesday condemning the violence and saying the protest was instigated by "criminal elements" and opposition.
He also said an inquiry had been formed to find the "underlying reasons for continued student unrest."
O'Neill said "a small group of students were violent, threw rocks at police and provoked a response that came in the form of tear gas and warning shots."
"Opposition members even made claims in the national parliament that students were killed when they knew this was false," O'Neill said.
A medical officer at the Port Moresby General Hospital said they had received 10 injured students, who were being treated.
"We do not have any knowledge of any fatalities. Two of those injured are serious," the officer told dpa over the phone.
Police Commissioner Gari Baki said in a statement there were no confirmed deaths and that nine students were receiving medical treatment at the hospital, local broadcaster EMTV news reported.
Two of the students were in serious condition and one had to be resuscitated and put on oxygen, the Post Courier newspaper said.
Schools and shops in the capital shut down following reports of looting, the paper said.
Australian Foreign Minister Julie Bishop called on all sides for calm to de-escalate the tensions.
"I know students have been shot, but we are still trying to determine whether there have been deaths and how many have been injured," she told reporters in Australia.
Papua New Guinea is a former Australian colony, and a number of Australian police are in the country as trainers and advisers.
The country is ranked among the top 30 most corrupt in the world, according to Transparency International.
Around 70 per cent of the 7 million inhabitants live in poverty.