Floodwaters triggered more than 2,000 landslides across much of the Balkans on Sunday, laying waste to entire towns and villages, disturbing land mines left over from the region’s 1990s war and displacing the warning signs that had marked the unexploded devices.

The Balkans’ worst flooding since such record-keeping began 120 years ago forced tens of thousands from their homes and threatened to inundate Serbia’s main power plant.

Authorities organized a frenzied helicopter airlift to get families to safety before the water swallowed up their homes. Many were plucked from roofs.

Water receded Sunday in some locations, laying bare the full scale of the damage. Elsewhere, authorities warned that floodwaters would keep rising into Sunday night.

“The situation is catastrophic,” said Adil Osmanovic, Bosnia’s refugee minister.

Three months’ worth of rain fell on the region in three days, leaving at least two dozen people dead.

The rain caused an estimated 2,100 landslides, which covered roads, homes and whole villages throughout hilly Bosnia.

The cities of Orasje and Brcko in northeast Bosnia, where the Sava River forms a natural border with Croatia, were in danger of being overwhelmed.

In Serbia, where towns and villages have been inundated, authorities braced for high water that could remain for several days.

Serbian Prime Minister Aleksandar Vucic said Sunday that 12 bodies were found in Obrenovac, site of the coal-fired Nikola Tesla power plant, Serbia’s biggest. Parts of the plant and a nearby mine that provides its fuel are underwater.

The floods and landslides raised fears about the estimated 1 million land mines planted during Bosnia’s 1992-95 war. Nearly 120,000 of the unexploded devices remain in more than 9,400 carefully marked minefields. But the weather toppled warning signs and, in many cases, dislodged the mines themselves.

Loose mines could create an international problem if floodwaters carry the explosives downstream. Experts warned that mines could travel through half of southeast Europe or enter the turbines of a hydroelectric dam.

From the air, the northeastern third of Bosnia resembled a huge muddy lake, with houses, roads and rail lines submerged. Officials say that about a million people — more than a quarter of the country’s population — live in the worst-affected areas.

Helicopters from Slovenia, Croatia and other European Union countries were aiding rescue efforts.

Large parts of eastern Croatia were underwater, too, with villages cut off and hundreds fleeing the flooded areas in boats and trucks.

In Serbia, more than 20,000 people have been forced from their homes.

— Associated Press