Three countries have warned their citizens to stay on guard when visiting U.S. cities rocked by sometimes violent protests that erupted after a string of police shootings of black Americans. The United States regularly issues travel warnings urging Americans to either avoid or exercise caution in countries marred by violence or political instability.

Now America is the focus of concern by foreign governments in the Middle East and Caribbean as protesters marched in U.S. cities throughout the weekend after police killed black men in Louisiana and Minnesota. READ MORE