The UK government said it was issuing its warning in response to the US alert. The warnings come after the State Department told US citizens in international locations to "exercise increased caution," after the US bombed three nuclear sites in Iran on Saturday. Iran has threatened to retaliate. In a statement, Qatar's Ministry of Foreign Affairs said a number of countries were urging precautions, but the embassy notice did "not necessarily reflect the existence of specific threats". "The security situation in the country is stable," the statement said, adding that "the relevant authorities are closely monitoring the situation and are ready to take all necessary measures to ensure the safety of citizens, residents, and visitors".

Qatar is home to the largest US military base in the Middle East, Al Udeid Air Base. About 8,000 US citizens live there, according to the State Department. The US has about 40,000 troops stationed in the Middle East. The message from the US Embassy was followed by warnings from other groups in Qatar, including several universities that asked students to go home. Bilateral relations between the US and Qatar are "strong", according to the State Department, which says Qatar has helped play a financial, political and military role in dealing with turmoil in the region. (BBC)