Dozens of people were killed and hundreds more were wounded in Brussels Tuesday in two separate bombings . The Islamic State group, also known as ISIS or ISIL, has claimed responsibility for the attacks, according to the Associated Press and The New York Times.Two blasts at the Brussels Airport — one that officials say was a suicide attack — and a bombing an hour later at the Maalbeek metro station near the European Union headquarters forced a citywide lockdown. European capitals tightened their own security in the wake of the violence, and President Barack Obama pledged in a speech from Havana to do "whatever is necessary" to help Belgian authorities seek justice for those killed, the AP reported. ISIS, which controls large swathes of Syria and Iraq, also orchestrated the November attacks in Paris , which killed 130 people, and is believed to be responsible for several bombings in Turkey, including Saturday's attack in Istanbul that killed four foreign nationals.Traveler Ilaria Ruggiano was at the airport when one of the blasts went off."We heard a big noise and saw a big flash. My mother went to the floor — she was hit. I just dropped my luggage and went to the floor. A kid came out, bleeding a lot. I tried to help him with a tissue, but it was not enough," she told The New York Times Ahead, photos of the Brussels attacks. This story contains images that some readers may find upsetting.