(CNN)Two brothers -- one at the Brussels airport, the second at a subway station in the same Belgian city -- blew themselves up during bloody terrorist attacks that once again rattled Europe to its core, the country's federal prosecutor told reporters Wednesday.
Prosecutor Frederic Van Leeuw identified Ibrahim El Bakraoui as one of the airport suicide bombers and his brother, Khalid El Bakraoui, as the man behind the deadly suicide blast about an hour later near the Maelbeek metro station.
There has been no official word yet on the identity of two other men seen, alongside Ibrahim El Bakraoui, pushing luggage carts through Brussels Airport in a photo released by authorities Tuesday.
One of them, dressed in light-coloring clothing and a hat, is thought to have placed a bomb at the airport and then left. But while two explosives went off within 37 seconds of each other shortly before 8 a.m., this third bomb -- described as the "heaviest" by Van Leeuw -- did not, instead being detonated by authorities later in a controlled explosion.
Belgian state broadcaster RTBF reported Wednesday that authorities had made at least one arrest in the aftermath of Tuesday's attacks, which the prosecutor says killed 31 people and wounded 270 more. Van Leeuw said two people were arrested Tuesday -- one in Schaerbeek and the other in Aaren -- but the person taken into custody in Aaren was interrogated and later released.
