The U.S. consulate in the Saudi city of Jeddah has advised citizens to exercise caution after unconfirmed reports that security forces had thwarted an alleged attack on a royal palace.
"Due to the possibility of ongoing police activity, American citizens are advised to exercise caution when traveling through the area."
There has been no official Saudi comment.
Accounts on social media claimed that a gunman and two security guards were killed in a purportedly aborted attempt to storm the palace that houses the Saudi royal court in the western city.
Saudi authorities announced Thursday that they had dismantled a cell linked to the Daesh that was planning to destabilize the oil-rich kingdom.
Last month, Saudi Arabia said that it had foiled a Daesh plot to carry out a suicide attack at the Defense Ministry in the capital, Riyadh.
Saudi Arabia has seen a series of deadly bombings that have been claimed by Daesh terrorists.