Thirteen army personnel were killed and one injured when a military helicopter crashed in the restive province of Saada in northwestern Yemen, the defence ministry reported.
The helicopter was carrying seven soldiers and a crew of four when it crashed shortly after it took off from a military airport in Kahlan area of Saada, some 240 km northwest of the capital, Sana'a.
All eleven died instantly, the ministry said in a statement. Two soldiers on the ground were also killed and a third injured, the ministry said.
Officials blamed the crash on a "technical fault" but gave no further details.
Saada has been the scene of fierce battles between the army and Shia rebels in the last five-and-a-half years.
The two sides agreed on a ceasefire that took effect at midnight Friday and remains in place.