The BBC reporter in Ethiopia's conflict-hit region of Tigray has been detained by the military.
Witnesses say Girmay Gebru, who works for BBC Tigrinya, was taken along with four other people from a café in the regional capital, Mekelle.
Mr Girmay is reported to have been taken to a military camp in Mekelle.
The BBC is yet to establish the reason for his detention, but has expressed its concern to the Ethiopian authorities.
A local journalist, Tamirat Yemane, and two translators - Alula Akalu and Fitsum Berhane, who were working for the Financial Times and the AFP news agency, respectively - have also been detained in recent days.
Ethiopia's government has been fighting rebel forces in Tigray since November. After months of an effective media blackout since the start of the conflict in Tigray, the government granted access to some international media organisations last week.
Both AFP and the Financial Times had received permission to cover the conflict.
Eyewitnesses told the BBC the operation to detain Mr Girmay was carried out by soldiers in military uniform.
A spokesperson for the BBC said: "We have expressed our concern to the Ethiopian authorities and are awaiting their response."
Fighting continues in Tigray despite the government declaring victory over the Tigray People's Liberation Front.
Hundreds have been killed and tens of thousands displaced.
There is international concern over growing reports of atrocities committed by all sides and the worsening humanitarian crisis, correspondents say.
An official of Ethiopia's ruling party recently warned that measures would be taken against people they said were "misleading international media".