Saudi Arabia on Thursday said it had expelled three employees of Syria's consulate in Jeddah.
A spokesman for the Saudi foreign ministry said the three had been told to leave for activities "incompatible" with their position, but did not elaborate.
Relations between Riyadh and Damascus have been tense since President Bashar al-Assad's bloody crackdown on dissent began in March last year.
In August, Riyadh withdrew its ambassador to Damascus and expelled the Syrian ambassador from Saudi Arabia in protest at the bloodshed.
The Syrian regime accuses Saudi Arabia, along with Turkey and Qatar, of arming the rebels fighting Assad's forces.
It was not known if the three consulate employees expelled had diplomatic status.