The town of Jablanica, some 70 kilometres (43 miles) southwest of Sarajevo, appeared to bear the brunt of the 24 hours of downpours, which cut it off from the outside world.

Jablanica, with a population of around 4,000, "cannot be entered or exited at the moment", the town's mountain rescue service said.

"We received information that five people have died in Jablanica, but we cannot officially confirm this yet," its spokeswoman Majda Kovac said.

In Kiseljak, some 20 kilometres west of Sarajevo, houses, gardens and cars were under water, an AFP journalist reported.

A large part of Bosnia's population is at risk due to heavy floods and landslides, the federal civil protection administration said in a statement.

Firefighters, police and utility companies were working to bring the situation under control in the affected areas, but more help is needed to mitigate the consequences of storms and rainfall, the federal civil protection administration warned.

Prime Minister of Bosnia's Muslim-Croat half Nermin Niksic wrote on social media platform X that the situation was "very serious as many citizens are still trapped in their houses.

"Unfortunately there were also human victims, but we still don't have all the information about that", he said.

Photos on local media from the Jablanica region showed mudslides coming up to roofs of houses and a mosque with only its minaret sticking out.

In neighbouring Croatia, weather authorities issued a warning for the northern Adriatic coast, Istria peninsula and central part of the country due to the heavy rains.

In a statement, it said that urban flooding and interruption of traffic, communications, electricity and water supply were expected.