U.S. counterterrorism officials say they believe video of an Al Qaeda recruiter threatening to smuggle a biological weapon into the United States from Mexico using underground tunnels is legitimate.

The video, which first aired on Al Jazeera in February, shows Kuwaiti dissident Abdullah Al-Nafisi telling a room full of supporters in Bahrain that Al Qaeda is surveying the U.S.-Mexico to figure out how to smuggle terrorists and weapons into the United States, the Washington Times reports.

In the video, which was obtained and translated by the Middle East Media Research Institute, Al-Nafisi also suggests that Al Qaeda might want to cooperate with members of U.S. white supremacist militias that hate the federal government:

"Four pounds of anthrax – in a suitcase this big – carried by a fighter through tunnels from Mexico into the U.S. are guaranteed to kill 330,000 Americans within a single hour if It is properly spread in population centers there. …What a horrifying idea; 9/11 will be small change in comparison. Am I right? There is no need for airplanes, conspiracies, timings and so on. One person, with the courage to carry four pounds of anthrax, will go to the White House lawn, and will spread this 'confetti' all over them, and then we'll do these cries of joy. It will turn into a real celebration."

Government officials told the Times they had no credible information that Al Qaeda has the means to accomplish this goal yet, but that they believe it is something the terrorist group seeks.

The video can be seen here.