The tourists' vehicle was stopped near the village of Karonge, around 60 kilometres from the regional capital Ziguinchor, a security source told AFP.
“There were four Spanish tourists. A man and three women were being driven by a Senegalese driver. They were kidnapped and (the women) raped before being let go,” local police chief Mamadou Samba told the public APS agency.
The same source confirmed the information to AFP, saying the women were dragged into the forest and assaulted.
APS and the source said around 5,000 euros worth of money was taken, a small amount of it in the local FCFA currency.
A medical source also told AFP one of the women was admitted to a health facility in nearby Diouloulou and was released a few hours later.
The Spanish foreign ministry would only confirm in Madrid that “something happened” affecting four of its nationals.
“The consul-general in Dakar is in touch with these Spanish citizens to offer them consular assistance,” a ministry spokesman said, adding it would not release details without the victims' permission.
Fourteen young men were slaughtered in execution-style killings in a protected forest on January 6th in the same region, reigniting debate over rebel and criminal groups operating in the area.
The attack — which comes at a delicate time for peace talks for Casamance — caused some to blame a group that has led a 35-year armed campaign for the region's independence.