Around 1,000 students and activists dressed in black participated in the protest in front of an East Java government building.

Holding posters that said "Reject the Military Law", and "The Military Should Return to the Barracks", protesters hurled rocks, sticks, and Molotov cocktails towards the police guarding the demonstration.

Police eventually used water cannons to disperse the protesters at around 7:00 pm (1200 GMT). 

"We received information that 25 people are being detained right now, but until now we are still unable to give legal assistance to them," Fatkhul Khoir, a human rights activist from the Commission for the Disappeared and Victims of Violence (KontraS) told AFP.

He said that some of the protesters taken to the police office looked bruised. 

The police did not respond to AFP's request for comments. 

The House of Representatives approved the amendment of the military law on Thursday, despite protests that it would expand the armed forces' role in civilian affairs. 

The revision to the armed forces law, pushed mainly by President Prabowo Subianto's coalition, was aimed at expanding the military's role beyond defence in a country long influenced by its powerful armed forces. 

The new law allows active military officers to hold a position in 14 government institutions without resigning, an increase from 10 institutions in the previous law. 

The amendment has sparked fears of a return to the era of late dictator Suharto, under whom Prabowo, an ex-general, once served and which saw military figures used to crack down on dissent.

Rights groups have said the change would enable officials to fill more civilian posts with active-duty military personnel and weaken legal checks on abusive officials. 

The passing of the law was immediately met with protests in several Indonesian cities. 

Police fired tear gas and water cannon to disperse the protesters after thousands of protesters attempted to storm into the parliament building in Jakarta last week.

Hundreds of students rallied outside the House building in Jakarta following the passage of the revisions. Dozens of them burned tires and some jostled their way through the gates, television footage showed.

Activists brought signs that read "New Order Strikes Back" and "Take the military back to the barracks".

Usman Hamid, the head of Amnesty International in Indonesia and who protested against Suharto during the New Order era, warned of the past returning.

"Activists were kidnapped and some have not returned home. And today it feels like we're going backwards," he said.

Military personnel were called in for security in the House building to assist police.

"The geopolitical changes and global military technology require the military to transform ... to face conventional and non conventional conflicts," Defence Minister Sjafrie Sjamsoeddin told lawmakers after the passing of the amendment.