Senegal said Tuesday that it had interrogated about 900 people over three days as part of efforts to prevent attacks by Islamist militants following a series of strikes in the region.
The former French colony has a reputation for stability in an otherwise turbulent region, having never suffered a major attack despite sharing a border with Mali, where al-Qaida-linked fighters have been active in desert areas for years.
But two high-profile attacks targeting foreigners in the capitals of Mali and Burkina Faso since November have added to signs that an Islamist insurgency is spreading, prompting Senegal to boost security.
"Nearly 900 people were called in for questioning in the context of the security campaign led by national police amid the terrorist threat," said police spokesman Henry Boumy Ciss, referring to a weekend campaign in the capital, Dakar, and the nearby city of Thies.
A second security source confirmed the information, saying 925 people had been questioned. Ciss said those interrogated were not targeted because they were terrorism suspects, but as part of a general vigilance campaign.
Most were subsequently released, but some were held and charged with a range of crimes not related to militant activity, such as drunkenness and traffic offenses, he added.
Seydi Gassama, executive director for Amnesty International in Senegal, said police were authorized to conduct such operations provided there were government instructions. However, the group will closely watch for any potential rights abuses in the heightened security context, given a history of police excesses, he said.
Diplomats have denied rumors of a specific threat to capitals of Dakar and Abidjan, both major hubs for Westerners working in the aid, diplomacy and financial sectors.
"We want to avoid an unnecessary psychosis among both Americans and Ivorians," the U.S. Embassy in Abidjan said Sunday, urging citizens to remain prudent.
But everywhere there are signs of heightened security. Police officers stop and search vehicles near Dakar's beachside restaurants, while armed guards are conducting patrols through Western-style shopping centers in both capitals.