KOTA BATU, Indonesia — Flash floods from torrential rains on Indonesia’s main island of Java killed at least 2 people and 8 others were missing, officials said Friday.

The National Disaster Mitigation Agency said rivers on the slopes of Mount Arjuno overflowed their banks on Thursday and their muddy waters inundated five hamlets in Kota Batu, a city in East Java province. It said 15 people were swept away and five were later rescued.

The agency chief, Ganip Warsito, said heavy rains are expected to continue and increase until February, partly because of a La Nina weather pattern.

Rescuers retrieved a body near Brantas river basin late Thursday and another body found early Friday, said the agency’s acting spokesperson Abdul Muhari in a statement. They are still searching for the 8 missing people, he said.

Relief efforts were hampered by power blocked roads covered with thick mud and debris.

Photos and videos released by the agency showed a damaged bridge, and cars and houses covered in thick mud.

Authorities were still collecting information about damage and possible casualties, Warsito said.

Seasonal rains frequently cause flooding and landslides in Indonesia, an archipelago of 17,000 islands where millions of people live in mountainous areas or near fertile flood plains.