The killing of al-Qaeda mastermind Osama bin Laden by U.S. forces in Pakistan on Sunday has led to a worldwide travel warning.

On Monday, the U.S. Department of State advised Americans to be vigilant and limit their travel, as there was an “enhanced potential for anti-American violence.”

Americans in countries where anti-American sentiment is strong were urged to stay indoors and avoid mass gatherings and demonstrations.

Travelers were also cautioned that for security reasons U.S. embassies and consulates might close or suspend services.

Though remaining at a heightened state of vigilance, the Department of Homeland Security has announced that it does not intend to issue any National Terrorism Advisory System alerts at this point.

Meanwhile, law enforcement agencies around the nation have stepped up security measures, as a preventative against possible terrorist retaliation.

In Los Angeles, Washington, D.C. and New York, subways, airports, bridges, federal buildings and tourism sites are seeing an extra level of security.

Travelers are being told to anticipate longer than usual airport security lines in the coming days.

By Adriana Padilla at PeterGreenberg.com.

Related Links: Travel.state.gov, Dept. of Homeland Security, Los Angeles Times, Associated Press

Related Links on PeterGreenberg.com:

• State Department Travel Alerts Vs. Travel Warnings
• Travel Tip: What State Department Alerts & Warnings Mean
• Terrorism & Security section
• Analyzing Post-9/11 Travel Safety & Security: Airports, Trains, International Hotels and Beyond
• Col. Jack Jacobs Analyzing Post-9/11 Transportation Security
• Check Your Attitude At The Airport, TSA Behavioral Officers May Be Watching
• Getting Through Airport Security More Quickly
• What New Airline Security Regulations Mean For Business Travelers