Nearly 2,000 people were arrested over the past week by police in Indonesia's Papua province for "illegal" pro-independence demonstrations before most of them were released, reports say.

The mass arrests coincided with the run-up to the anniversary of the resource-rich territory's controversial incorporation into Indonesia in 1969.

Veronica Koman, a lawyer based in the Indonesian capital, Jakarta, told Al Jazeera dozens of people were arrested on Tuesday, with at least 19 children detained in the town of Fakfak, about 1,500km from Jayapura, the provincial capital of Papua province.

"Six have been admitted to hospital today," she said, citing sources on the ground but providing no reasons for the hospitalisation.

In the largest mass arrests known so far, 1,449 people were arrested on Monday in Jayapura, 200 in Merauke, 45 in Semarane, 42 in Makaffar, and dozens more across the region, Koman said.

Victor Yeimo, chairman of the West Papua National Committee, which organised the pro-independence rally, told Al Jazeera that most of the nearly 2,000 people arrested had been released but hundreds were still in detention.

Papua province and West Papua make up the western half of an island north of Australia, with independent Papua New Guinea to the east.

Foreign journalists have been banned from reporting in Papua and local journalists barred from covering the latest protests.

Police told Al Jazeera there were no reports of violence but that the protesters did not have a permit to hold the rally.

"At least two people were arrested while handing a petition to the police," Koman said.

"It's unclear what legal justification the Indonesian authorities could have for the arrests. We are currently investigating what the reasons could be."

Separatist conflict

Papua has seen a long-running and often violent separatist conflict since being incorporated into Indonesia after a widely criticised UN-backed referendum in 1969. Dutch colonial rule ended on May 1, 1963.

Indonesian President Joko Widodo has made several trips to Papua since taking office in 2014 and has promised to bring development to the impoverished region after decades of neglect.

His government has also released several political prisoners and pledged to resolve cases of human rights violations.

But security forces still maintain a strong presence in the restive region and are often seen as taking a heavy-handed approach to peaceful demonstrations, activists say.