(CNN) -- The State Department has issued a worldwide caution urging U.S. citizens traveling or residing abroad to exercise much greater caution than usual in the wake of the U.S. military strikes against terrorist targets in Afghanistan and Sudan.

Large crowds and other situations in which anti-American sentiments may be expressed should be avoided, the State Department said.

Americans should be aware that embassy operations are currently suspended in Somalia, Sudan, Republic of Congo-Brazzaville, Democratic Republic of Congo and Guinea-Bissau. No U.S. consular services are currently available in these countries.

The United States does not maintain diplomatic or consular posts in Afghanistan, Iraq, Iran, Libya and North Korea, and therefore no support services are available to Americans in these countries. U.S. diplomatic posts worldwide are taking appropriate security precautions.

Family members and non-emergency personnel of the U.S. embassies in Kenya and Tanzania have been authorized to depart. In Albania, Eritrea, and Pakistan, non-emergency personnel and family members have been ordered to depart. Consular services in these countries have been reduced to minimal levels and in most cases to emergency citizens services only.