King Khalid military City, Saudi Arabia: Warplanes roared overhead, tanks rumbled across the desert and smoke filled the sky on Thursday during the final stage of what Saudi Arabia has billed as the region's biggest-ever military exercises.
About 20 nations from the Middle East, Africa and Asia are taking part in the last day of the so-called "Northern Thunder" manoeuvres in the desert north of the kingdom, which began 12 days ago.
Regional leaders including Egypt's President Abdel Fattah al-Sisi, Sudan's Omar al-Bashir and Pakistani Prime Minister Nawaz Sharif joined Saudi Arabia's King Salman to attend the conclusion, the official Saudi Press Agency said.
Taking place near Hafr al-Batin city in northeastern Saudi Arabia, close to the Kuwaiti and Iraq borders, the manoeuvres are the "most important and largest in the region's history", according to Saudi authorities.
A two-hour mock battle featuring fighter jets, attack helicopters and tanks was among the final events of the exercises, which Saudi Arabia has described as a show of regional unity.
Riyadh has adopted a more assertive foreign policy since Salman took the throne early last year following the death of his half-brother king Abdullah.
It is leading a mainly Arab coalition fighting rebels in Yemen, is taking part in US-led air strikes against the ISIS and has offered to send special forces to fight ISIS in Syria.
"Northern Thunder" is also taking place after tensions escalated between Sunni-dominated Saudi Arabia and its regional Shiite rival Iran, who back opposing sides in Syria and Yemen.
Authorities have released few details of the extent of the exercises.
But Saudi Brigadier General Ahmed al-Assiri told reporters this week they were aimed at preparing to tackle the region's "terrorist menace" and were not directed against Iran.
