One year on from the Kanjuruhan football stadium disaster that killed more than 130 people in Indonesia, families of the victims are calling on authorities to reopen investigations and declare the incident "a serious human rights violation."

Video footage aired by CNN affiliate CNN Indonesia showed emotional scenes as families gathered at the National Police Headquarters in the capital Jakarta on Wednesday to demand justice.

Families, many of whom had traveled to Jakarta from Malang Regency where the tragedy took place, wore black T-shirts with the message: "Never Forget, 1 October, 2022," and carried photos of deceased loved ones.

Some 135 people were killed and hundreds more were injured in a crush as crowds rushed for the exits following a clash between fans and police that saw security forces fire tear gas within the stadium. Investigations by government-sanctioned fact-finding teams concluded the crush was primarily caused by police shooting tear gas at spectators.

But until now, only five people -- three police officers and two organizers -- have been put on trial. Families have criticized their prison sentences -- of between one and two years -- as being too light.

"(Our) hope is for justice... harsh as possible punishment for the 135 lives lost," said one woman demonstrating outside the police HQ who lost her daughter in the fatal crush.

Similar gatherings took place on Monday, when dozens visited the offices of Komnas HAM, a state human rights institution.

"The Kanjuruhan tragedy was a gross human rights violation," said Imam Hidayat, a spokesperson for the Kanjuruhan Tragedy Advocacy Team, who called on the Attorney General's Office to form an independent team to investigate the tragedy. "There is a conflict of interest if the investigation is done by police," he said.

Also among the demonstrators was a man named Daniel, whose daughter Elvi Duali died at the stadium. "It isn't fair," Daniel said. "Even after a year, we (the victims' families) still have not received justice."

Located in East Java, the Kanjuruhan Stadium was used mostly for soccer matches, with a supposed capacity of 38,000 spectators.

But there were around 42,000 tickets sold for the game on October 1, 2022, when one of the worst disasters in the sport's history unfolded.

A clash between a number of Arema FC fans and police prompted security forces to fire tear gas into enclosed areas of the stadium. Panicked fans then attempted to flee the choking smoke, triggering a crush at the exits.

Many of those killed were trampled to death or died from asphyxiation and other breathing problems, officials said.

Among the dead were 33 children, including one as young as 3.

Survivor accounts emerged alleging excessive force by armed riot police officers kicking and beating people at the scene.

President Joko Widodo has said the stadium would be demolished and rebuilt. But one year on and the building still stands, largely abandoned, with graffiti and posters condemning the tragedy.

Rights groups told CNN that "a year had pass but nothing had changed since the tragedy."

"The ongoing legal process still does not fulfill a sense of justice for victims or their families," said Usman Hamid, executive director of Amnesty International Indonesia.