Indonesian security services have launched an operation targeting separatists in the province of Papua after 31 construction workers were shot dead, authorities said on Tuesday.

"This is the worst attack launched by the armed criminal group recently amid intensified development by the government," Papua police spokesman Suryadi Diaz told The Associated Press.

Police are trying to recover the bodies, but Diaz said the separatists had scattered them throughout the district, which is known as a rebel stronghold.

The workers were employed by the state-owned construction company Istaka Karya as part of a government-sponsored infrastructure project aimed at fostering economic development in the region.

Indonesian Public Workers Minister Basuki Hadimuljono said work stemming from the infrastructure project would be "suspended given this incident."

Read more: A look at the Papua conflict — Indonesia's 'low-level insurgency'

The region has seen bouts of deadly violence erupt between authorities and rebels for years

Half a century of conflict

The province is home to a low-intensity conflict between Papua rebels fighting for independence and government forces.

The former Dutch colony declared independence in 1961, but two years later was occupied by Indonesian forces. Papua separatists launched an insurgency following a controversial UN-backed referendum in 1969 that saw the province formally annexed by Indonesia.

Indonesia has maintained a strong grip on the mineral-rich province, with human rights groups criticizing the government for maintaining tight restrictions on access and press coverage.

The murders come days after Papua separatists celebrated what they describe as their Independence Day on December 1.

Read more: Fighting for a forgotten cause in West Papua

Every evening, DW's editors send out a selection of the day's hard news and quality feature journalism. You can sign up to receive it directly here.

The Caucasus to the Koreas: A world of frozen conflicts Eastern Ukraine/Crimea In 2014, Russia annexed Crimea and started providing support to rebels in eastern Ukraine. The conflict in Ukraine quickly gained an international dimension and triggered a renewed standoff between Russia and the West that has extended as far afield as Syria.

The Caucasus to the Koreas: A world of frozen conflicts Korean Peninsula North and South Korea are technically still at war, having signed no peace treaty to end the Korean War. The demilitarized zone, or DMZ, is a 2-kilometer (1.2-mile) strip separating the countries. The border is one of the tensest and most heavily militarized in the world.

The Caucasus to the Koreas: A world of frozen conflicts South Ossetia and Abkhazia South Ossetia and Abkhazia are post-Soviet breakaway republics outside the sovereign control of Georgia. They are backed and recognized by Russia and only a handful of other states. The conflict turned hot during 2008 Russian-Georgian War, which effectively kicked Tbilisi's forces out of the republics.

The Caucasus to the Koreas: A world of frozen conflicts Cyprus A 1974 invasion by Turkey in response to a coup attempt to join the island with Greece split the island between the self-declared Turkish Republic of Northern Cyprus and the internationally recognized Republic of Cyprus in the ethnically Greek south. The two communities' leaders are engaged in complicated reunification talks. Both sides have expressed hope for a settlement this year.

The Caucasus to the Koreas: A world of frozen conflicts Nagorno-Karabakh Azerbaijan and Armenia went to war over Nagorno-Karabakh until the two sides reached a truce in 1994. Since then, the territory - ethnically Armenian but formally Azerbaijani - has been under the control of local Armenian forces and the Armenian military. The conflict has had periodic violent flare-ups, most recently with a bout of fierce fighting in April.

The Caucasus to the Koreas: A world of frozen conflicts Western Sahara Morocco annexed Western Sahara after colonial power Spain withdrew in 1975, setting off a conflict with the Polisario Front, which demands self-determination. In 1991, a UN-brokered ceasefire put a halt to fighting. However, a promised referendum on self-determination has failed to materialize, threatening to upend a shaky peace.

The Caucasus to the Koreas: A world of frozen conflicts Kashmir Kashmir is divided between India and Pakistan, which have fought two wars over the predominantly Muslim region. India accuses Pakistan of arming rebels fighting for independence or union with Pakistan. The emotionally charged issue is especially dangerous given that both countries have nuclear weapons.

The Caucasus to the Koreas: A world of frozen conflicts Trans-Dniester Trans-Dniester is a pro-Russia breakaway region of Moldova. The sliver of territory bordering on Ukraine split from Moldova, triggering a 1992 war. Russia maintains peacekeepers in the region. Some analysts say Trans-Dniester is a potential hot spot used by Russia to keep Moldova from becoming closer to the West. Author: Chase Winter



ls/rc (AP, Reuters, AFP)