In all, five people were killed in violent incidents across the restive eastern province overnight Wednesday and early Thursday, police said.

Calls for Papuan independence have grown ahead of the elections and police said the violence could be part of an effort to undermine the vote.

"The incidents ... indicate that there are people who want the elections to fail," Papua police chief Bagus Ekodanto said.

Police opened fire when around 100 people attacked their post in Abepura town just outside the provincial capital Jayapura.

Senior police officer Domingus Rumaropen said the attackers threw a bomb that hit a fence and exploded about 1.30am before officers were able to drive them away.

"The police opened fire and chased them. One of them was shot and fell into a drain. Three bullets hit him," Rumaropen said, adding nine of the attackers were arrested.

Fourteen men, all students, have been arrested in connection with the attack, police said.

Meanwhile, three people were killed and two injured in stabbing attacks in the highland town of Wamena late on Wednesday.

"Three motorcycle-taxi drivers died from the attacks. Two civilians are in critical condition and being treated in Wamena hospital," local police chief Mulya Hasudungan Ritonga said.

In other incidents, a building at the Abepura university was set ablaze while a fuel depot on the island of Biak caught fire in suspicious circumstances, killing a four-year-old girl.

Pro-independence sentiment runs high in Papua, which sits on the western end of New Guinea island and is populated mainly by ethnic Melanesians.

Indonesia took formal control of the region in a 1969 UN-sponsored vote by select tribal elders widely seen as a sham and the area has seen a long-running insurgency waged by poorly armed pro-independence guerrillas.