The two messages were written in Russian saying an 'explosion' would happen on the city's metro on Wednesday 8 March.
ADVERTISEMENTA terrorist attack in Brussels is "unlikely", according to the Belgian Federal Police, after the European Commission received two threatening emails, warning of an "explosion" on the city's metro.
When approached by Euronews on Wednesday, both the Federal Police and Federal Prosecutor's Office said that the "threat was taken seriously", but that "nothing was found" during a sweep of the Brussels underground line.
This came after the US embassy in Belgium released a security alert warning of a "threat of a possible metro attack to be conducted today". They urged people to "use caution when travelling in and around Brussels and avoid crowds."
According to local media reports, the Commission was contacted on two separate occasions, once on February 16 and a second time on March 3, after which it alerted the authorities late on Tuesday. Both emails were written in Russian.
Belgian newspaper Le Soir reports that the warning from the sender said: "In light of the EU's continued aggressive policies I hereby warn you of major terrorist attacks on EU territory."
A statement seen by Euronews from the European Parliament to its MEPs said that it was "monitoring the situation closely" alongside the national authorities.
The federal police say that while the risk of an attack is low, they are remaining vigilant. An investigation is now ongoing to find the person responsible.