Pakistan carried out airstrikes in eastern Afghanistan on Wednesday, escalating months of cross-border conflict between the two neighbors.

Afghanistan’s Taliban government said the strikes killed 13 civilians, including 11 children, while Pakistan said it targeted militant hideouts and killed 26 militants.

The attacks ended more than a month of relative calm following repeated clashes and failed peace talks.

Pakistan accuses Afghanistan of sheltering the Pakistani Taliban (TTP), which it blames for deadly attacks inside Pakistan, while Afghan Taliban officials deny the allegations, CBS News has reported.

Both sides dispute casualty figures, with Pakistan rejecting reports of civilian deaths and vowing to continue its counterterrorism operations.