UPDATE: 4:12 a.m. EDT — Papua New Guinea's Police Commissioner Gari Baki said Wednesday that 23 people, believed to be students at the university, were injured, the Associated Press reported. He denied reports claiming that four persons were killed. Baki added that the head of the emergency ward at Port Moresby General Hospital informed the police that five of the injured were in a critical condition.

Original story:

The Papua New Guinea police opened fire on students protesting against Prime Minister Peter O’Neill Wednesday in the country’s capital city, Port Moresby. The students have been demanding the resignation of the prime minister for weeks over allegations of corruption and mismanagement.

Unconfirmed reports say that four people have been killed in the shooting and several injured. However, authorities have denied the reports. Police Commissioner Gari Baki said that no deaths were reported but nine students who were injured are receiving medical treatment at Port Moresby General Hospital, the Associated Press (AP) reported.

O’Neill said in a statement that a small group of protesters had grown violent and threw rocks at the police who then used tear gas and fired warning shots.

Australian Foreign Minister Julie Bishop reportedly said, “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. ... We call on all sides to be calm and to de-escalate the tension and certainly call on all sides to respect the peaceful and lawful right to protest."

Lawmaker Gary Juffa’s personal assistant, Joe Duhube, told the AP that when Juffa had spoken to the students after the shooting, he was told that “one of the students got killed instantly and others are in serious and critical conditions.”

In 2012, Papua New Guinea was ranked one of the most corrupt countries by Transparency International. O’Neill was accused of fraud by the national anti-corruption watchdog in 2014, which issued a warrant for his arrest. The warrant has not been carried out so far.

Thousands of students at the University of Papua New Guinea have been protesting against the leader for weeks. Classes were officially suspended last month. BBC cited local news channel EMTV that said classes were supposed to resume this week.

O’Neill has denied all allegations and refused to step down.