The US embassy in Mauritania said Friday it had received information about "near-term" attacks targeting Americans in the capital Nouakchott, urging its nationals to remain alert.
The warning came in the wake of appeals by the Islamic State (IS) group for its followers to carry out attacks across the world, the statement said, urging Americans to be vigilant especially when "frequenting locales associated with Westerners".
"The US government has received information that terrorist groups are planning to carry out near-term attacks against places where US citizens congregate in Nouakchott," said a statement on the embassy's Facebook page.
"When going out, avoid being part of large, highly visible groups of Westerners and avoid sitting in areas that are easily visible from the street. Be particularly alert when frequenting locales associated with Westerners," it advised Americans.
Contacted by AFP, a Malian security source said: "Even if nowhere has zero risk, one should not worry excessively about the current security situation in the country.
"We believe we are in control of the situation, both on our borders and within the country, where dangerous groups are closely monitored," added the source, requesting anonymity.
In September the government denied that a suspected Islamist militant cell uncovered by the authorities had pledged allegiance to IS, describing the group as "amateurs".
Several Islamist militant with links to IS have been convicted in the Islamic republic, in the Maghreb region of western north Africa, which suffered repeated attacks in the 2000s, including deadly kidnappings.
Mauritania jailed three men for between five and 10 years for links with IS in June 2015, with the court shown a video in which all three pledged allegiance.