Two Westerners are reported to have been kidnapped by gunmen in a bar the capital of Niger on Friday.
Armed men wearing turbans have forced them into a car in the city of Niamey, witnesses said.
The abducted men are believed to be French nationals.
A French foreign ministry source, while not confirming the nationalities of the victims, the ministry was aware of the reports.
It was not immediately clear who was responsible for the kidnapping.
A number of Westerners have been kidnapped in Niger over the last few years, often ending up in the hands of the Sahara-based North African wing of al Qaeda, AQIM.
Previous attacks have taken place further to the north, where the influence of the Niamey government is weaker and a mix of rebels and local bandits has long operated.
Most of the hostages have been released after demands are made and, reportedly, millions of dollars in ransom payments paid, even though officials never confirm money changes hands.