Madrid: At least two people died overnight after a bus plunged into a river while crossing a bridge in Spain's northwestern Galicia region, the emergency services said Sunday.

The accident occurred on Saturday night near Vigo and the border with Portugal. The regional La Voz de Galicia newspaper said the bus was carrying people visiting their loved ones jailed in Monterroso in central Galicia.

The emergency services said two corpses had been recovered while two others, including the bus driver, had been rescued and taken to hospital.

"There could have been more people inside the bus," they said on Twitter and posted a photo of the vehicle in turbulent waters.

Three people were missing, several Spanish media outlets reported, but this was not verified by officials.