Filep Karma and Yusak Pakage were detained in late 2004 in Jayapura for displaying the Morning Star flag as part of a ceremony commemorating the 1961 declaration of Papuan independence. They were sentenced in 2005 to 15 and 10 years in prison, respectively.

Tuesday was the 48th anniversary of both the pro-independence Free Papua Movement (OPM) and the day the Netherlands recognized Papua’s right to self-rule. Before its independence was recognized by the world, Indonesia incorporated the vast, resource-rich territory in 1969 after a UN-backed referendum held among a few hundred tribal leaders.

“The aim is to keep putting pressure on the Indonesian government to remind them we have not forgotten these two prisoners,” Amnesty International regional director Folabi Olagbaju told Agence France-Presse as he led some 40 protesters outside the Indonesian Embassy in Washington.

“It is outrageous that the [Indonesian] government can arrest and imprison people at a nonviolent, peaceful protest for raising a flag,” he said. “There needs to be freedom of expression, and they [the government] shouldn’t be afraid of that.”

“These two should not have spent a day in prison, much less five years.”

Indonesian courts have handed down stiff penalties, including life sentences, to people caught with separatist symbols such as the Papuan flag.

Meanwhile, Papua Police Chief Brig. Gen. Bekto Suprapto said the 13 activists detained in Jayapura on Tuesday had disrupted public order.

“They were charged, not because of the demonstration, but for refusing to disperse,” he said on Wednesday.

The 13 were arrested as police dispersed about 40 activists who had gathered in Jayapura carrying posters with separatist symbols banned by the state.

Separately, the Indonesian Armed Forces (TNI) said on Wednesday it would allow the police to take the lead in securing Papua, including in the legal process against the 13 activists arrested on Tuesday.

“In a situation of civil order, which is in the hands of the police. The TNI will only assist them when needed,” TNI Chief Gen. Djoko Santoso said.

More than 170 people are currently imprisoned in Indonesia for peacefully promoting separatism in the country, most of them from Papua or the eastern Maluku islands, according to Human Rights Watch.