Police in Guinea-Bissau say they are holding five al-Qaeda members over the killing of a group of French tourists in Mauritania last month.
Two Mauritanians were detained at a hotel in the capital Bissau on Friday.
Police say are among the men who killed the French tourists, and that they have confessed to being al-Qaeda fighters.
Three other suspected militants, also described as Mauritanian, were later picked up as they tried to photograph French police in the city.
Guinea-Bissau officials say they have information suggesting one of the three was involved in the killing of the four French holidaymakers.
They were shot by gunmen as were picnicking by the roadside near Aleg in southern Mauritania on 24 December.
Extradition
French police took part in the operation that led to the arrests in Guinea Bissau, French media reports say.
AFP news agency quotes sources close to the investigation as saying the two men initially arrested crossed into Senegal after the shooting, and made their way south to Guinea-Bissau.
Mauritania has sought their extradition.
At least nine people have also been arrested in Mauritania. Prosecutors say they are linked to a group allied to al-Qaeda.
The Mauritanian authorities say the suspects are thought to belong to al-Qaeda in the Islamic Maghreb - a group that has its roots in the Algerian civil war of the 1990s.
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