The United States has issued an emergency warning that terrorists may be planning to abduct Westerners in the Saudi Arabian capital.
It advised American citizens in Riyadh to vary their travel routines and keep a low public profile, the BBC reports.
It did not call on them to leave Saudi Arabia and the US embassy in Riyadh is expected to continue operating normally.
Britain's Foreign Office has not changed its travel advice for Saudi Arabia, which warns that the risk of terrorism remains high.