Some 400 trained Islamic State jihadists have been sent to Europe to carry out attacks, security experts told the Associated Press on Wednesday.
The warning comes a day after a terror cell in Belgium launched attacks on a Metro Station and airport in Brussels killing at least 32 people.
The terror group, which claimed responsibility for the attack on Tuesday evening, has reportedly dispatched a network of semiautonomous cells to bring terror to the continent as it loses substantial ground to airstrikes in Syria.
The forewarning came from European and Iraqi intelligence officials, according to AP, as well as a French politician who talked of camps in which Isis fighters are specifically trained to hit western targets.
Earlier on Wednesday, the suspected bombmaker in November's Paris terror attacks was one of two suicide bombers who killed themselves in Brussels airport, Belgian authorities revealed.
Najim Laachraoui was thought to be on the run after discarding a failed bomb at Brussels airport. However, officials said his DNA was that of one of the suicide bombers. As such, the identity of the third man -- called the "man in white" -- remains unknown.
PA reported that Laachraoui's death adds credence to the assumption that both Brussels and Paris were carried out by the same Islamic State cell.