Yamamoto, a video and photojournalist for Tokyo-based Japan Press, was killed in clashes between rebels and Syrian government forces in the northern city of Aleppo, according to news reports and Japan's Foreign Ministry.
In footage released by Japan Press and shot shortly before her death, Yamamoto is seen traveling with the rebel Free Syrian Army to an area that had been bombed when gunshots were heard. Aleppo was the scene of a heavy government attacks that day.
Yamamoto was among a group of journalists that included Kazutaka Sato, her husband and colleague. In a telephone interview with Japan's NTV and described by Reuters, Sato said: "We saw a group of people in camouflage fatigues coming toward us. They appeared to be government soldiers. They started random shooting. They were just 20, 30 meters away or even closer." The other journalists scattered and escaped harm, he said, but Yamamoto was struck by the gunfire. She died at a nearby hospital.
Deputy Foreign Minister Faysal Mekdad denied that government forces killed Yamamoto and said she was killed by "armed groups," The Associated Press reported.
Yamamoto, 45, was a veteran correspondent, who covered the war in Afghanistan in 2001 and the U.S.-led invasion of Iraq in 2003, according to Japan Press, which produces documentaries and news footage, according to its website.