The Department of Homeland Security on Wednesday told airlines about a potential new shoe-bomb threat and urged them to pay extra attention to flights from overseas into the United States.

Several officials familiar with the advisory told NBC News that "very recent intelligence" considered credible warns of possible attempts to attack passenger jets using explosives concealed in shoes.

The bulletin to airlines urges screeners to use the explosive trace detection swabs to check shoes that are worn and in carry-on bags.

After assessing the information, the Department of Homeland Security advised airlines earlier Wednesday of the possible threat and urged greater security scrutiny on U.S.-bound flights.