The accident happened on Saturday but rescue crews were hampered by heavy rain and adverse conditions during the night.
The death toll from a bus crash in northwest Spain has risen to seven after the body of a woman was discovered on Monday.
Rescuers had been searching for survivors after the bus fell from a bridge into a river on Christmas Eve.
Authorities say the accident happened around 21:30 GMT (22:30 CET) on a national road near the small town of Cotobade in Galicia, close to the border with Portugal.
There were eight or nine passengers on the bus at the time of the crash, as it traveled between the cities of Lugo and Vigo.
Two of the passengers -- the driver and a female passenger -- were rescued and taken to hospital.
Investigators are still trying to establish the cause of the accident.
The bodies of the first two victims were discovered on Saturday evening, while the bodies of three more people were found late Sunday morning near the wreckage of the bus, according to a Guardia Civil spokesperson.
The number of victims was initially unclear because the driver was in shock and "had a doubt" about the number of people who were in the bus at the time of the accident, the Guardia Civil told reporters.
According to authorities, five of the people who died were a young Peruvian woman living in Galicia, and four Spanish locals.
Among the passengers on the bus were people who had come to visit relatives held in the Monterroso prison in central Galicia on Christmas Eve, according to the regional daily La Voz de Galicia.
Heavy rain at the time of the crash
The driver of another vehicle first raised the alarm with rescue crews, when they saw the safety rail had been destroyed on the bridge. Rescuers also got a call from the bus, which helped locate the wreckage.
The bus had fallen from the bridge and plunged down a ravine into a river below.
The local mayor described the accident as "a tragedy without words," and praised the professionalism of the rescue crews who arrived at the scene.
Those rescue efforts were hampered by heavy rain which fell during the night and caused the water level of the Lerez river, where the bus fell, to rise sharply.
Adverse weather conditions forced rescuers to suspend the search for several hours during the night. The search finally resumed at dawn with the help of a number of mountain rescue units, cavers, and a helicopter.
According to the authorities, the causes of the accident are not yet known, although bad weather may have played a role. According to the Guardia Civil spokesman, the bus driver tested negative for alcohol and drugs.
"We do not yet know the causes (of the accident) with certainty" but "it is true that the weather conditions were very bad last night", confirmed the president of the region of Galicia, Alfonso Rueda.
On Twitter, the leader of the People's Party (PP, right) Alberto Nuñez Feijoo, a native of Galicia, which he led for 13 years, sent his "condolences to the families of the victims" and thanked those involved in the search and rescue operation.