A female Japanese journalist was killed yesterday while covering clashes in Syria's Aleppo, the Britain-based Syrian Observatory for Human Rights said, adding that three other reporters were missing.

The Japanese reporter was killed at Suleiman al-Halabi, a district in the east of Syria's second city where troops and rebels were locked in clashes.

The NGO added that one of two missing Arab reporters is a Lebanese woman and the other is a man working for a US media outlet. The third missing reporter is Turkish.

A video posted by militants on YouTube showed a female body lying in a room. It was presented as the corpse of the Japanese journalist, and said she was killed by militia allied to President Bashar al-Assad's troops.

A prominent injury could be seen on her right arm. Next to her, an Asian-looking man appeared to be asking for medical assistance.

AFP was unable to independently confirm the authenticity of the video, or the information presented in it.