More than 100 U.S. Peace Corps volunteers have been evacuated from the West African country of Burkina Faso.

The volunteers were evacuated due to unspecified “security concerns,” according to a statement posted on the organization’s website on Sunday.

There were 124 volunteers working in Burkina Faso at the time.

“The Peace Corps has been closely monitoring the safety and security environment in Burkina Faso and will continue to assess the situation.

“The Peace Corps looks forward to a time when volunteers can return while underscoring that the safety and security of its volunteers are the agency’s top priority,” said the statement.

Burkina Faso has witnessed a rise in activity by Al-Qaeda affiliates and the establishment of a small faction affiliated to the Islamic State militant group (ISIS) in recent months.

Gunmen killed at least 18 people after besieging a Turkish restaurant in the capital, Ouagadougou, in August in the latest major attack in the country.

The attack was similar in style and took place less than two blocks from a similar attack carried out in January 2016, which killed about 30 people and was blamed on Al-Qaeda affiliates.

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