Though federal and local law enforcement officials said there are no known threats aimed at New York City in light of Osama bin Laden's death anniversary, New York police are beefing up security measures as a precaution.

U.S. Navy SEALs killed bin Laden on May 2, 2011, when they raided his compound in Abbottabad, Pakistan. Al-Qaida has reportedly vowed revenge.

Law enforcement officials told the media that the New York City Police Department is planning a security surge on Wednesday at all major transportation hubs to provide added security for commuters. Federal air marshals were also moved overseas to guard U.S.-bound flights, according to reports.

NYPD spokesman Paul Browne told Bloomberg that some of the sites include Grand Central Terminal, Pennsylvania Station and Times Square.

U.S. officials and those from allied countries are now concerned about body bombs. These are explosives with no metal parts, implanted in the stomach of an individual, and are said to be difficult to detect.

The intelligence community has been aware for some time of a Yemen-based terrorist bomb maker who has been attempting to perfect the so-called body bomb technique, Browne told Bloomberg. However, we're not aware of any specific plot at the anniversary involving the airlines or any other target.

These types of dangerous explosives have been a concern for U.S. officials since 2009 when there were two incidents involving militants who spent time with Yemen-based al-Qaida in the Arabian Peninsula, according to Reuters.

ABC News reported that Ibrahim Hassan al-Asiri, an al-Qaida bomb maker in Yemen, is the mastermind behind the body bomb. He is accused of putting a bomb inside his younger brother to carry out a failed assassination attempt on Saudi Prince Muhammed bin Nayif, the country's counter-terrorism chief, in 2009.

Reuters reported that authorities also found that the bomb used in that incident was identical to the one Nigerian militant Umar Farouk Abdulmutallab used when trying to blow up a Detroit-bound airliner on Christmas Day 2009.

White House counter-terrorism advisor John Brennan said the  al-Qaida group in Yemen is the greatest threat to the U.S., noting that it continues to seek the opportunity to strike our homeland.