The Saudi coastguard have arrested a group of Iranians who attempted to infiltrate the country by sea near the northeastern frontier with Kuwait, authorities said.
Seized were 14 Iranians who had been dropped off on shore by a boat and the driver of the boat, who was chased and captured by patrol boats as he headed out, Eastern Province coastguard spokesman Colonel Khaled al-Arqubi in a statement.
"Fourteen Iranians were captured on Friday night while attempting to infiltrate into the kingdom through the eastern coast in the area of Khafji," he said.
"Coastguard boats chased the boat that dropped them and his driver was arrested. The boat is Iranian (registered) and the man who drove it is an Iranian national," he added.
Arqubi said that the captured men were being questioned about their motives.
Relations between Tehran and Riyadh have been tense for years over many political and security issues, including Iran's controversial nuclear programme, which scares its Arab neighbours across the Gulf waters.
Shiite-dominated Iran has also been at odds with the Sunni heavyweight over the conflict in Syria, as Tehran backs the regime of President Bashar al-Assad while Saudi Arabia supports the rebels.
And predominantly Shiite Muslim Iran is upset over Saudi support for the Sunni dynasty in the Gulf kingdom of Bahrain, after it sent in troops last year to help crush pro-democracy demonstrations by the country's Shiite majority