Jakarta, Dec. 3 -- Indonesia is extending weather-modification operations in North Sumatra and Aceh to keep air routes open for delivering relief supplies to flood-hit areas, the National Disaster Mitigation Agency (BNPB) said on Wednesday.

Head of BNPB's Disaster Data, Information and Communication Center Abdul Muhari said the cloud-seeding operations are aimed at reducing thick clouds and strong headwinds that frequently disrupt helicopter operations over hilly terrain, delaying aid deliveries to isolated communities.

He spoke during an online briefing late Wednesday on the government's response to the floods and landslides affecting Aceh, North Sumatra and West Sumatra.

Poor weather often forces air crews to wait for safe flying con...