Rescuers have recovered the victims from a bus that ran off a bridge and plunged into a river on Christmas Eve, killing six passengers.

The driver and another passenger were injured, Spanish authorities said.

The blue roof of the half-sunk vehicle could be seen in the Lérez river about 30 metres below the bridge.

Emergency services were alerted by a motorist who saw the broken railing on the bridge as he drove in heavy rain.

Part of a blue bus is seen after it plunged into a river near Pontevedra in northwestern Spain. Photo / AP

The Spanish Guardia Civil said a total of eight people were on the bus.

The two survivors were rescued Saturday night and taken to hospitals.

The bodies of the dead were retrieved Sunday.

Regional president Alfonso Rueda said the bad weather conditions were a possible cause of the accident.