A rescue mission is under way after a vehicle carrying three people was washed away by floodwater.

Police, State Emergency Service crews and swift water rescue teams were called to Roma-Taroom Road in Waikola, about 310 kilometres north-west of Toowoomba in the Western Downs, at 3.20pm on Wednesday.

Police said the three people managed to escape from their vehicle after it was washed away when they tried to drive through a flooded crossway.

A Queensland Fire and Emergency Services spokeswoman said swift water rescue crews reached the trio about 6pm and were working to get them to safety.

The three people were on dry land, but trapped between a swollen creek and river.