The Belgian federal police said Wednesday it remained “vigilant” after it received an email Tuesday threatening a terror attack targeting the Brussels underground metro system.
“At the moment, we remain very vigilant, as is necessary,” said a spokesperson for the Belgian federal police, in charge of security in metro stations.
The police carried out a sweep in the metro during the night, but “found nothing suspicious,” the spokesperson added.
According to a spokesperson for the Brussels civil prosecutor — which has taken over the investigation — the risk of a “real attack” is considered “unlikely.”
A spokesperson for the Belgian National Crisis Center — charged with organizing the security response in case of a terror attack — said the threat was being evaluated, but confirmed that an attack was unlikely.
The threat was picked up by the American embassy in Brussels, which issued a warning to U.S. citizens, recommending they “use caution when traveling in and around Brussels.”
Brussels suffered a major terrorist attack at the city’s international airport and at the Maelbeek metro station in March 2016, which killed 32 people.