(AP) — Democratic lawmakers who appeared in a social media video urging U.S. troops to defy “illegal orders” say the FBI has contacted them to begin scheduling interviews, signaling a possible inquiry into the matter.

The news came after the Pentagon announced it is investigating Democratic Sen. Mark Kelly of Arizona over potential violations of military law related to the video, and President Donald Trump has accused the lawmakers of sedition “punishable by DEATH” in a social media post.

In the video, Kelly, who was a fighter pilot before becoming an astronaut and then retiring at the rank of captain, told troops that “you can refuse illegal orders,” while other lawmakers — all veterans of the armed services and intelligence community — called on U.S. troops to “stand up for our laws … our Constitution.”

Kelly and the other lawmakers didn’t mention specific circumstances in the video. Troops, especially uniformed commanders, do have specific obligations to reject orders that are unlawful, if they make that determination. However, the U.S. military legal code will punish troops for failing to follow an order should it turn out to be lawful.