MANILA, Philippines (AP) — Philippine communist guerrillas said Thursday they have decided to end a 36-day cease-fire declared during the coronavirus pandemic because of military attacks.

The Communist Party of the Philippines said it would not extend the cease-fire, which expired Thursday night, and ordered New People’s Army rebels to return to an offensive posture. The rebels heeded the U.N. chief’s call last month for a global halt to fighting during the outbreak.

The party said in a statement that the refusal of President Rodrigo Duterte’s administration to halt attacks “made the further extension of the New People’s Army cease-fire impossible.”

Duterte also ordered a cease-fire last month, saying troops were helping fight the pandemic in the countryside. The government cease-fire ended on April 16 and was not extended because officials accused the rebels of staging attacks.

The communist insurgency has raged mostly in the countryside for more than half a century in one of Asia’s longest-running rebellions. The military estimates there are still about 3,500 armed guerrillas after battle setbacks, infighting and surrenders reduced their numbers, although the rebels claim they have more fighters.

Duterte launched peace talks with the rebels when he took office in mid-2016. But the negotiations, brokered by the Netherlands, eventually bogged down with both sides accusing the other of continuing to carry out attacks.