RIYADH - A Saudi military helicopter that crashed in Yemen killing 12 Saudi soldiers was likely hit by "friendly fire", military sources said Wednesday.
The soldiers, including four officers, died Tuesday when the helicopter went down in Yemen's Marib province, the Saudi-led Arab coalition fighting Iran-backed Huthi rebels said in a statement.
"As the Saudi helicopter was not identified by the ground operations centre, the air defence system was triggered automatically," a senior Yemeni military official said.
A source familiar with the details of the incident said the helicopter appeared to have been hit by friendly fire "from automated systems".
Such incidents can happen if pilots fail to communicate with systems on the ground, the source, who asked to remain anonymous, told AFP.
The Yemeni defence ministry's 26sepnews.net news website also reported on Tuesday that the helicopter had been hit by mistake.
It cited a senior Yemeni officer who said the aircraft was shot down five kilometres (around three miles) from its landing site after "a technical error that caused the air defence system to make an incorrect reading."
The website said the helicopter came down "a very long way" from rebel positions, beyond the range of their weaponry.
Coalition spokesman General Ahmed Assiri, contacted by AFP, did not confirm or deny the friendly fire reports, saying an investigation was under way and it was "too early to adopt any hypothesis".
The coalition began air strikes in Yemen in March 2015 in support of President Abedrabbo Mansour Hadi's internationally recognised government in its fight against Iran-backed Huthi rebels.
Saudi Arabia and the United Arab Emirates, which play key roles in the coalition, have suffered its heaviest losses, with dozens of soldiers killed.
In September 2015, a rebel missile strike on a coalition base in Marib killed 67 coalition soldiers, most of them Emiratis.
The United Nations says that more than 7,700 people have been killed since March 2015 in poverty-stricken Yemen, which also faces a serious risk of famine.
Seven ceasefires brokered between government and rebel forces by the United Nations have failed, while UN-backed peace talks have repeatedly broken down.