Formerly called Irian Jaya, the region was incorporated into Indonesia after Dutch rule, in 1969, in a process seen by tribal leaders as a sham.

Indonesian authorities keep a tight grip on the province, and on media coverage of it.

Indonesian police chief Bagus Eko Danto said the journalists did not have a permit to cover the protests.

"Nicholas Jouwe's group had already left the area in the morning but they also covered the rally, despite not having permits," he said.

The four journalists included the NRC Handelsblad newspaper's Jakarta correspondent Elske Schouten and three documentary makers.

Referendum call

On Tuesday, about 1,000 protesters marched on the provincial parliament to call for a boycott of national elections, scheduled for 9 April.

Surrounded by a heavy police presence, they demanded a referendum on independence.

The protesters chanted "Free Papua" and "Boycott the election" and carried banners calling for an end to Jakarta's heavy-handed military presence in the region.

The 85-year-old Nicholas Jouwe arrived in Indonesia last week, calling for peace between the Indonesian government and Papuans during a meeting with Welfare Minister Aburizal Bakrie.

Sporadic protests and regular security crackdowns have marked the long-running insurgency by the pro-independence Free Papua Movement (OPM).

About 100,000 Papuans - a sixth of the population - have died in military operations.

Last week, suspected rebels attacked a security post, killing a government soldier.

The remote resource-rich province is home to the Grasberg mine, which is operated by Freeport-McMoRan Copper and Gold Inc of the United States.

The mine has the world's largest recoverable copper reserves and largest gold reserves.

Indonesia took over Papua from the Dutch in 1963 and formalised its sovereignty six years later through a stage-managed vote by about 1,000 community leaders.