Over 2,000 Saudi militants fighting abroad: ministry

"The number of Saudis proven to be in conflict areas is 2,093," interior ministry spokesman General Mansour al-Turki told daily newspaper Al-Hayat.

Some 1,540 fighters are in Syria, where jihadists have flocked since the Islamic State group seized control of large swathes of land in 2014.

Another 147 are in Yemen, which is the base of al-Qaeda in the Arabian Peninsula (AQAP), considered by Washington to be the most dangerous affiliate of the global terror network.

Another 31 are believed to be in Afghanistan or Pakistan, Turki said, while only five are believed to be in neighbouring Iraq.

The official said 73 Saudis had also been detained abroad "on charges related to acts of terrorism", without providing further information.

Last March, The New Arab carried out an investigation into the background of 121 members of IS' "martyrdom unit", and revealed Saudi nationals made up the largest number of suicide bombers.

The New Arab analysed 121 documents of an official IS file named "the martyrs", which was leaked by Syrian news site Zaman al-Wasl, revealing that suicide bombers from more than 20 countries have signed up for the so-called "martyrdom unit".

Saudis are at the top of the list of IS militants who have enlisted themselves to be trained to carry out suicide attacks with 32, choosing death by blowing themselves up as opposed to roles as rank and file soldiers or "inghimassi solders" – troops who submerse themselves into the enemy's line with no intent to come back alive.

On the forms, most of the Saudi militants filled in their nationality as "Gulfi" or used the term "the land of the two Holy Mosques" instead of Saudi Arabia.

The latest figures came just weeks after a US official claimed at least 50,000 militants have been killed - two-thirds of them in Iraq - since a US-led coalition began a bombing campaign in late 2014.

Agencies contributed to this report.