Six mortar shells fell in a remote area of eastern Saudi Arabia near the kingdom's borders with Iraq and Kuwait without causing damage, a border guard spokesman said Thursday.

The spokesman, General Mohammed al-Ghamidi, said Saudi authorities were in "direct contact" with their neighbours to identify the source of the shelling and "prevent it taking place again".

"Six mortar rounds fell Wednesday in an uninhabited area near Al-Awja border crossing... in Hafr al-Batin in (the oil-rich) Eastern Province, and no damage was caused," the official SPA news agency quoted Ghamidi as saying.

The report gave no further details of the incident. Residents said Saudi warplanes were flying over the area early on Thursday.

Hafr al-Batin, a desert region near Iraq and Kuwait, was a former command headquarters for US army forces during Operation Desert Storm that prompted the pullout of Iraqi troops from Kuwait in 1991.