Papua New Guinea's Prime Minister Peter O'Neill has faced public anger over financial mismanagement and a long-running corruption investigation that he has been seen as dodging.
Students have protested for months demanding his resignation. They have also boycotted classes, leading the university last month to indefinitely suspend the semester.
O'Neill has refused to step down, saying the corruption allegations were "of questionable political intent."
The opposition has already made three previous attempts to unseat O'Neill in the parliament. A fourth attempt is ongoing.
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.
To avoid arrest, his critics say, he has sacked several high-level government officials and ministers, and secured court injunctions.
The Anti-Corruption Directorate holds an arrest warrant for the prime minister, but a judicial review is still pending before the courts.
In April, the police commissioner shut down the directorate, the country's only anti-corruption body that was looking into the corruption allegations, citing "administrative reasons." It led to a split in the police ranks.
Later, the Supreme Court asked the commissioner to re-open the unit, but the anti-fraud officers now have to submit their cases to a "vetting committee" before they can arrest suspects.