JAKARTA (Reuters) - Indonesian police fired tear gas in several areas of Jakarta on Monday as a protest against legal reforms descended into running battles, causing traffic gridlock and chaotic scenes in parts of the central business district.

A riot police officer fires tear gas during a riot following protests near Indonesian Parliament building in Jakarta, Indonesia, September 30, 2019 in this photo taken by Antara Foto. Antara Foto/Aditya Pradana Putra/ via REUTERS

Several thousand students, activists and workers had gathered near parliament to oppose a new law that critics say undermines the fight against graft, and a new criminal code outlawing sex outside marriage, and criminalizing insulting the president’s honor.

A list of student demands that has been circulated on social media also includes stopping forest fires and removing a heavy military presence in the restive easternmost area of Papua.

Students have led the rallies across the country since last week, some of the biggest since 1998 student protests fueled unrest that led to the fall of former strongman leader Suharto.

On Monday, police fired tear gas to break up crowds, including near the Atma Jaya Catholic University in the city center, where a medical center had been set up, said Bunga Pertiwi, a bank worker who was helping injured students.

“So many cars were trapped. Many turned around. It was so chaotic,” Pertiwi said by telephone.

A subway station near Jakarta’s financial center was also closed and a commuter line halted as protesters fled from tear gas.

Earlier, police said they fired tear gas after protesters who refused to disperse and threw rocks, bottles and fireworks at officers, according to the state Antara news agency.

Asfinawati, who heads the Legal Aid Institute, condemned using tear gas near a designated medical zone.

A Twitter account that tracks the protests, @AksiLangsung (direct action), reposted several tweets saying protesters needed oxygen, water and medication.

In another spot near the commercial center of Tanah Abang, a car parked in front of a police station was torched, news website Detik.com reported, citing a firefighter.

The portal also said 37 students were taken to Pertamina Hospital for treatment, quoting a hospital official.

Monday was the last day of parliament’s session and lawmakers officially agreed to delay to its next term a vote on the criminal code bill. A new parliament will be sworn in on Tuesday.

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Chief security minister Wiranto warned in a televised news conference demonstrators not to damage public facilities in expressing their criticism of the government.

“Demonstrations that break laws, demonstrations that attack officers, damage and burn stuff, are not demonstrations anymore, but a movement by rioters,” the minister said.

More than 20,000 police and military personnel were deployed to maintain security in the capital, according to media.

Students also staged protests in the cities of Yogyakarta, Solo and Bandung in Java.

More than 200 protesters in Bandung were treated in a university after clashes with police, a dozen of which had since been moved to a hospital, Detik.com reported.

Last week, President Joko Widodo said he would consider revoking the law governing the anti-corruption agency and ordered police restraint after the death of two student protesters, one of whom police said died of bullet wounds.

Sandi Saputra Pulungan, an activist with the Indonesian Forum for the Environment (Walhi), said the protests would continue until all of their demands were met.

“We see that in Indonesia, our democracy is in danger. It’s as though we’re not in a democracy, but rather we are returning to the era of the New Order,” Pulungan said, referring to the 32-year rule of the late president Suharto, who used the army to maintain tight control and contain opposition.