Floods in central Norway after a weekend of heavy rain have claimed no human victims. (Representational)

Heavy rainfall in Norway has caused rivers to overflow their banks, with a waterway in the west of the country sweeping away more than 100 sheep, police said Monday.

"Firefighters and police are now trying to rescue stranded sheep," More and Romsdal regional police wrote on Twitter.

"Currently there are reports of more than 100 sheep carried off by the waters," it added.

"I have never experienced anything like this," sheep farmer Harald Kragnes told the newspaper Verdens Gang.

"There are many dead sheep floating down the river," he added.

Floods in central Norway after a weekend of heavy rain and winds have so far claimed no human victims.

However, around 25 houses and a retirement home have been cut off due to rising water levels, according to public broadcaster NRK.