Protesters take to the street to face off with Indonesian police in Manokwari, Papua on August 19, 2019.
CNN  — 

Thousands of protesters in the provincial capital of Indonesia’s West Papua have set fire to a local government building amid widespread demonstrations sparked by alleged police discrimination against Papuan students.

The Indonesian provinces of Papua and West Papua have for decades been wracked by a long-simmering and occasionally violent separatist movement, with flare-ups common.

On Monday morning, crowds marched through Manokwari, the capital of West Papua, setting fire to the parliament building, cars, and tree tires.

Videos on social media show the parliament building billowing black smoke, and deafening chants from large crowds on the streets – a rare public protest in the highly militarized region. Footage shows protesters bearing signs that read, “Stop racism.” Police in Manokwari responded to the protests Monday with tear gas.

“This is unpredictable – the masses are so angry,” said Veronica Koman, a human rights lawyer in Indonesia, adding that the protests were “triggered by the racist attacks.”

The unrest first began on Saturday in Surabaya, on Indonesia’s Java island, a national holiday marking Indonesian Independence from Dutch colonial rule. Papuan students were accused of throwing the Indonesian flag into a ditch, leading a clashes with a crowd of angry local residents, according to CNN affiliate CNN Indonesia.

Protesters set fire to cars, tires, and the local parliament building in Manokwari.

Activists and Papuan students claim that police sent to quell the disturbance abused the students with racist terms, fueling the outrage that is driving Monday’s protests in Papua and West Papua.

“Police threw tear gas into the dormitory before they entered the dormitory and arrested 43 students,” said local non-profit organization Legal Aid Institute Surabaya in a press release.

Police confirmed on Monday that they had responded to the unrest in Surabaya, but denied arresting any students. A spokesperson from the East Java Police Department told CNN that the police in Surabaya had brought 43 Papuan students to the police station on Friday to halt the clashes, and that the students were later brought back to the dormitory where the clashes had taken place.

Authorities said the situation in Manokwari is beginning to calm and streets are clearing as people return home. The protests are now “under control,” said West Papua Deputy Governor Mohamad Lakotani.

Lakotani added that protesters are demanding an apology from the East Java local government for its alleged mistreatment of the Papuan students in Surabaya.

Although things have cooled in Manokwari, there are still ongoing protests in Sorong City, also in West Papua, and in Jayapura, the capital city of neighboring Papua province.

The two provinces, which used to be Dutch colonies, became part of Indonesia in 1969 after a highly contested referendum in which just over 1,000 Melanesian locals were handpicked to vote.

The outrage over the flag allegations and the rapidly escalating, violent protests underscore the volatility of the region and the tumultuous relationship between roughly four million Papuans and the central Indonesian government.

“West Papua is a militarized zone. People’s everyday life is colored by harassment and intimidation at the hands of security forces,” said Benny Wenda, a Nobel Peace Prize nominee in the UK who leads a global push for rights in Papua.

Earlier this year, as the Indonesian general election neared, Papuans demanded a vote to be released from Indonesian rule – to no avail.