Banda Aceh – At least 12 people, including three policemen, were killed in an upsurge of violence in the Indonesian province of Aceh, police and rebels said Friday.

The three special force police officers were shot when about 10 gunmen attacked a police van in central Aceh on Friday, said Supt. Yatim Suyatno of the local police. Two other officers were injured in the ambush in Serambang village, Suyatno said. He said the attackers were members of the Free Aceh Movement.

Earlier in the day, Supt. Abadan Bangko, chief of North Aceh police, said 14 soldiers and police officers were wounded in five separate clashes Thursday with the rebels. Abu Sofyan Daud, a rebel leader in northern Aceh, said six civilians died and 11 other were captured by Indonesian security forces during Thursday's fighting.

Also Thursday, police found the bodies of three civilians, including a village chief, who had been abducted earlier by unidentified gunmen in central Aceh. Police said another civilian was still unaccounted for after Wednesday's abduction.

Separatists in Aceh, a gas-and oil-rich province, have been fighting since 1975 for independence from Indonesia. At least 5,000 people have been killed in the past decade. The latest deaths brought to 87 the number of people killed in Aceh since a truce went into effect June 2.