Washington: Twelve Saudi soldiers, including four officers, were martyred on Tuesday when their helicopter went down in Yemen, the Arab coalition fighting  Iran-backed Yemeni rebels said.

The Saudi Black Hawk “fell during operations in the province of Marib” east of Sana’a, the coalition said.

“The causes of the incident are being investigated.”

Coalition spokesman General Ahmad Assiri told AFP it was “too early” to comment on the causes of the crash, which is one of the deadliest incidents involving coalition forces in Yemen.

The incident came ahead of a visit by US Defence Secretary Jim Mattis to the region.  Ahead of his trip, Mattis said the US wants a return “as quickly as possible” to UN-backed Yemen peace talks. The United States provides limited military support to a Saudi-led coalition which for two years has been fighting in support of Yemen’s internationally-recognised government against rebels supported by Iran.

“The crisis should be handed to a team of UN negotiators that can try to find a political solution as quickly as possible,” he said before flying to Riyadh where he will meet leaders today.

It is necessary to end the “firing of missiles provided by Iran against Saudi Arabia” as well as “the death of innocent people in Yemen”, he added.

Al Houthi rebels have consistently fired ballistic missiles into Saudi Arabia.

On his tour, Mattis is looking  for broader contributions and new ideas to fight Islamist extremism.

American goals include expanding the US-led coalition against the Daesh group in Iraq and Syria, but also combating Al Qaida, whose Yemen branch is posing particular worry as it uses ungoverned spaces in the Arab world’s poorest country to plan attacks on the United States.

On his weeklong trip, Mattis also is scheduled to visit Egypt, Israel, Djibouti and  Qatar, which hosts the US military’s main Mideast air operations centre.