Russian sociologists Maxim Shugaley and Samer Soueifan were detained at the airport in the capital of Chad.
Since September 19, they have remained under guard at N'Djamena airport.
The detainees, Maxim Shugaley and Samer Sueifan, were not given any explanation for the reasons for their detention, RIA Novosti writes.
No charges have been brought against Russian sociologists.
The Russian citizens have been detained and remain at the airport in the capital of the Republic of Chad since September 19 without charges or explanation.
Sociologists have visited Chad before and have not encountered any problems.
Sources emphasized that sociologist Shugaley last made contact on September 19.
He reported that he was not allowed to cross the border at the airport. Later, contact with him was lost.
Russia may have questions through the Ministry of Foreign Affairs regarding the legality of the detention of Russian citizens at the airport in Chad.