The N1 TV reported that 21 people died and that dozens went missing in the Jablanica area, 70 kilometres (43.5 miles) southwest of Sarajevo.
The government is due to hold a press conference later.
“There are some villages in the area that still cannot be reached, and we don’t know what we will find there,” said a spokesperson for the Mountain Rescue Service whose teams are involved in search.
Heavy rain overnight halted search, Bosnian media reported, but as it stopped the search continued. In Donja Jablanica many houses were still under rubble.
Nezima Begovic, 62, was lucky. Her house is damaged, but she came out unhurt.
“I heard people screaming and suddenly it was all quiet. Then I said everyone is dead there,” she told Reuters.
Due to flash flooding on Friday a quarry above Donja Jablanica collapsed and rubble poured over houses and cars in the village.
“Everything was white (from the stones and dust that came down from the quarry), My friends’ house was gone. I heard screams,” Imamovic told Reuters.
Bosnia’s election commission decided to postpone local elections this weekend in municipalities affected by floods, but to carry on with voting elsewhere.
The floods follow an unprecedented summer drought which caused many rivers and lakes to dry up, and affected agriculture and the supply of water to urban areas throughout the Balkans and much of Europe.
Meteorologists said extreme weather changes can be attributed to climate change.
