JAKARTA (AFP, DPA) - A second Indonesian student has died after protesters clashed with police on Indonesia's Sulawesi island during a rally against legislation that critics fear would undermine freedoms and anti-corruption efforts, an official said on Friday (Sept 27).

"This morning, another student, who was critically injured, died because of bleeding in the head," chief provincial ombusdman Mastri Susilo told dpa.

The 19-year-old engineering student died in hospital of blunt-force injuries to his head sustained in riots that erupted in Kendari city on Sulawesi island on Thursday, local hospital director Sjarif Subijakto told AFP.

The victim's relatives also confirmed the teen's death early Friday. The precise circumstances surrounding his death were not clear.

"His father has accepted his death, he just wants to know how it happened," relative Rahmat, who gave only his first name, told AFP in Kendari. "But his mother is still in shock."

It was the second fatality directly linked to days of street battles across the South-east Asian nation that have left hundreds injured and sparked calls for a probe into allegations of police brutality.

Police fired tear gas to quell rock-throwing protesters who gathered outside the legislative council building in Kendari, the capital of South-east Sulawesi on Thursday.

One student died of a bullet wound during the violence, the authorities said.

The 21-year-old university student in Kendari - where the local parliament building was torched - was rushed to hospital suffering from a chest wound and later died.

Questions have swirled around his death as police denied responsibility.

"It was a gunshot wound, but I cannot confirm whether it was a live bullet or rubber bullet," said Kendari doctor Yudi Ashari, who treated the 21-year-old victim.

On Friday, when asked by an AFP reporter if the first victim was killed by a live round, the forensic doctor who performed his autopsy answered "yes" several times.

Police have insisted that officers deployed to the Kendari riots were not equipped with live rounds or rubber bullets.

This week, tens of thousands of students across the country have been holding daily protests, which have often turned violent, against revisions to the criminal code, which include the criminalisation of sex outside marriage, co-habitation and insulting the president.

Passage of the reforms has now been delayed.

The violence in Kendari followed clashes in Jakarta on Tuesday that left more than 260 students and 39 police injured as security personnel and protesters faced each other outside the national parliament building, police said.

The proposed changes to the criminal code would see consensual sex outside of marriage punishable by up to one year in prison, while a couple living together without being married could be jailed for up to six months.

Anyone who insults the president or vice-president could be handed a prison term of up to 4½ years. This was decriminalised by the Constitutional Court in 2016 after a legal challenge by citizens.

The protesters also demanded the government revoke recent revisions to a law governing the country's anti-corruption commission that activists warn could severely threaten the body's independence.

The demonstrations are among the biggest since mass street protests in 1998 brought down the three-decade Suharto dictatorship, and they come several weeks before re-elected president Joko Widodo is to kick off a second term.

President Widodo's administration has sought to portray the mass demonstrations as being hijacked by agitators aiming to disrupt government - and suggested they were similar to deadly post-election riots that paralysed Jakarta in May.