JAKARTA (Reuters) - Three Indonesian soldiers were killed in a clash with dozens of rebels in the eastern province of Papua, the military said late on Thursday, the latest deaths amid high tensions and violence in the restive region.

Papua, a former Dutch colony and the western part of New Guinea island, was incorporated into Indonesia after a widely criticized U.N.-backed referendum in 1969.

A long-running separatist movement in the region has seen an increase in violence in recent months.

A team of 25 soldiers was ambushed by up to 70 “armed criminals” carrying military-standard weapons and traditional weapons, the Indonesian army said in a statement.

“The team fought back until they were able to drive the armed criminal group back into the forest. Three soldiers died in the attack,” the army said.

Up to 10 rebels were thought to have been killed, but only one of their bodies was found, it added.

Two military helicopters dispatched to evacuate the soldiers also came under fire, the army said.

A spokesman for the rebel group, known as the West Papua Liberation Army, said at least five soldiers had been killed and Indonesian forces had set fire to several houses in the Nduga area. Sebby Sambom did not say how many casualties the group suffered.

Indonesia has deployed hundreds of soldiers to build a major highway connecting the remotest parts of the resource-rich province, after 16 construction workers were killed by separatists late last year.

Since then, fighting between rebels and the Indonesian military has caused hundreds of villagers to flee the Nduga area in western New Guinea island.

President Joko Widodo, who faces an election in April, has vowed to finish the highway project as part of his promise to develop Papua, Indonesia’s poorest region.