ISIS on Tuesday claimed credit for the Belgium attacks by way of its Amaq News Agency. Rita Katz, director of SITE Intelligence Group, tweeted a statement from the agency that reads in part, "Islamic State fighters carried out a series of bombings with explosive belts and devices ... in the center of the Belgian capital Brussels, a country participating in the international coalition against the Islamic State." It states "several" fighters used explosive belts at the airport following the use of guns there; one belt-wearing bomber detonated himself on the metro.
Meanwhile, the Guardian reports by way of local media that Belgian police are searching for a man clad in a light jacket who may have info on the airport attack; he was photographed with two other men, whose identities are also unknown. See the photo here. Local media has released video taken in the Zaventem airport in the aftermath of the attack. (Read more Brussels attack stories.)