"Due to security concerns, the Department of State has authorised the departure of family members and non-emergency employees of the US embassy and consulates (in Saudi Arabia) on a voluntary basis," the department said on Wednesday. 

"Private American citizens should evaluate their own security
situations and should consider departing the country," it said in a travel warning that replaced an existing alert issued just nine days earlier. 

"The US government continues to receive indications of terrorist threats aimed at American and Western interests, including the targeting of transportation and civil aviation," the department said. 

Earlier warnings

The department issued the 8 December travel warning just two days after US diplomats in Riyadh were ordered not to venture outside of the capital's diplomatic quarters except on "essential business". 

"The US government continues to receive indications of terrorist threats aimed at American and Western interests, including the targeting of transportation and civil aviation"

Statement from US department

Similar restrictions were placed on diplomats posted at the US
consulates in Jeddah on the Red Sea coast and Dhahran on the east coast. 

Earlier, on 3 December, the State Department issued a travel alert for the kingdom, less than 24 hours after the US embassy in Riyadh warned that a specific housing compound in Riyadh was under surveillance by "terrorist elements". 

"Credible information indicates that terrorists continue to
target residential compounds in Saudi Arabia, particularly in the Riyadh area, but also compounds throughout the country," it said.