Amnesty International Indonesia is urging the police to release a number of high-school students who were arrested for wearing Morning Star independence flag attributes during a parade in Nabire, Central Papua.

Amnesty International Indonesia Executive Director Usman Hamid said based on information they received, at least six students were arrested by police during a senior high-school (SMA) graduation celebration on Monday May 6.

"We call on the authorities to immediately free all the students who were detained for no apparent reason and carry out a fair investigation of teh acts of violence that allegedly occurred", said Hamid said in a written statement on Tuesday May 7.

According to Hamid, the arrests were accompanied by alleged acts of violence by police against students which is unacceptable. He said the expression of happiness through a peaceful procession is not a crime.

Hamid is also of the view that the symbol of the Morning Star represents a cultural expression, so it should not be a reason for the authorities to arrest anyone without due legal process.

"The police and the government should emulate Gus Dur's [former Indonesian president Abdurrahman Wahid] approach towards indigenous Papuans. Cultural symbols such as the Morning Star flag were accommodated because it's a peaceful expression", he said.

Based on information obtained by Amnesty, the students celebrated their graduation by holding a parade on a main road while wearing their school uniforms.

Some of them drew motives of the Morning Star flag on their uniforms, which the authorities see as being a symbol of the Free Papua Organization (OPM).

A similar celebration was also carried out by SMA students in Dogiyai regency.

But the celebration in Nabire ended with the arrest of the students accompanied by alleged violence by the authorities. So far, the identity of the six arrested students is still unknown. The students were said to have been taken to the Nabire regional police station.

CNN Indonesia has contacted the head of Papua regional police public relations division, Senior Commissioner Ignatius Benny Ady Prabowo, to ask about the arrests in Nabire, but as of this report being written he has not responded.

Earlier, Prabowo said the police had asked for clarification regarding the students' parade wearing the Morning Star attributes. "We have asked for clarification from the Dogiyai Polres [district police] related to photos of the event that were circulated on a WhatsApp group", said Prabowo on Monday.

Meanwhile, quoting from by Detik South Sulawesi, Dogiyai police chief Police Commander Sarraju said the long-march by the Dogiyai 2 State SMA students was indeed to celebrate their graduation. He claimed that the police who were on patrol in the area were prohibited from entering the school.

"Indeed (on Monday) morning at around 9.30 am our officer conducted patrols and monitored the announcement of 12th grade graduation at the Dogiyai SMU [State High School] 2 led by Second Police Inspector Agustinus Rirey and officers", he said on Tuesday.

"But when they wanted to enter the school grounds to appeal to students not to carry out the parade or long-march they were prevented by several students standing guard at the school gate", he added.

The police, he said, are looking into the actions of the Dogiyai 2 State SMA students who celebrated their graduation wearing clothes with pictures of the Morning Star flag. The school principal and four teachers have already been questioned over the incident.

"The Dogiyai police criminal investigation unit has conducted a clarification with the school principal and teachers, as many as four people, in relation with yesterday's incident", said Dogiyai district police chief Police Commander Sarajju.

Sarajju said that Dogiyai 2 State SMA school principle Fredy Yobee has apologised for the incident claiming that he and the teachers did not have prior knowledge of students' actions.