Central government officials declined immediate comment.
"The five crew members are being questioned. They are Iranians," said the official in Haja province, which borders Saada province, site of most of the fighting between government forces and the rebels.
Yemen sees the hand of Iran behind the rebellion but Tehran denies any role. Yemeni government officials have said Iranian media supports the rebels and President Ali Abdullah Saleh has suggested that Iranian religious figures provide funding. (Reporting by Mohamed Sudam, Writing by Firouz Sedarat, editing by Jon Boyle)