The exercise on Saudi Arabia's east coast, dubbed Gulf Shield-1, involved combat search-and-rescue drills as well as naval warfare and air operations, officials said.

Saudi King Salman presided over the closing ceremony of the drills, which he said highlighted a "unified alliance" between over 24 countries to combat military threats.

"The event is... meant to demonstrate our ability to take joint military action, the region's readiness to support Arab unity and its capacity to deter any threats," military spokesman Abdullah Subaei was quoted as saying in a Saudi information ministry statement.

"This exercise demonstrates that we have the cooperation of friendly nations, our experience and expertise to deal with those threats."

On Sunday, King Salman slammed Iran's "blatant interference" in the region as Arab leaders met in the kingdom for their annual summit.

Riyadh and Shiite rival Tehran back opposing sides in a range of hotspots across the mainly Sunni Muslim Middle East, including Lebanon, Syria, Iraq and Saudi Arabia's southern neighbour, Yemen.

Saudi Arabia in March 2015 launched a coalition of Arab states fighting to roll back Iran-backed Huthi rebels in Yemen and restore the country's internationally-recognised government to power.

Last November, Saudi Crown Prince Mohammed bin Salman presided over the first meeting of an Islamic counter-terrorism alliance involving around 40 Muslim countries, as he vowed to "pursue terrorists".