New People's Army rebels. Pic: AP.

MANILA, Philippines (AP) — A Philippine official says a communist guerrillas’ move to free four abducted police officers has sparked hopes for resuming stalled peace talks but a major obstacle remains.

New People’s Army rebels freed the officers they seized in an attack on a southern police station three weeks ago as a goodwill gesture to promote peace negotiations with the government. The military and the rebels declared a weeklong regional cease-fire to foster the releases.

Presidential adviser Teresita Deles said Wednesday the move “constitutes a potential building block” for the talks’ resumption.

But no solution is in sight for a rebel demand for the release of detained comrades, which the government rejected and which led to the talks’ collapse.

The rebels have been fighting since 1969 in one of Asia’s longest-running Marxist insurgencies.