The armed militants, who have no passports on them, plan to "reach Europe by boat via Turkey and Greece," Belgium's Derniere Heure daily newspaper reported, citing a message that local anti-terrorism authorities distributed earlier this week. "They will split into two groups, with one targeting Belgium and the other one heading to France."
The newspaper described the attack as "imminent."
Daesh may be losing on the ground in Iraq and Syria, but the group is still capable of wreaking havoc across the globe.
"Anyone who has opened a newspaper over the last 18 months will know that Islamist terrorist atrocities in France are now disturbingly common. The massacre in Paris last November, carried out by [Daesh], was the most gruesome proof of this," counterterrorism and national security analyst Robin Simcox asserted.
The November night of terror in France is not an isolated incident. Two days ago, on June 14, Larossi Abballa, a 25-year-old who pledged allegiance to Daesh, stabbed Jean-Baptiste Salvaing, a 42-year-old French police officer, and his companion Jessica Schneider, a 36-year-old police administrator, in the Paris suburb of Magnanville.
In March, Belgium was rocked by twin suicide bombings at an airport and a subway station that claimed the lives of 32 people. Terror threat levels have remained high in both countries since the November attacks in the French capital.
The latest warning comes on the heels of the deadliest mass shooting in the US history that left 50 people dead and 53 wounded in Orlando, Florida on June 12. The attacker, identified as 29-year-old Omar Mateen, is said to have sworn allegiance to Daesh.
On Wednesday, French President Francois Hollande and Prime Minister Manuel Valls warned that tackling terrorism will take a long time. Hollande referred to it as "a long war" that affects the whole world. Valls suggested that "this war will take a generation."
Earlier in May, Daesh released a message referring to the Islamic holy month of Ramadan as the time "of conquest and jihad." The group's spokesman Abu Muhammad al-Adnani, who is believed to have made the recording, called on Daesh followers "to make it a month of calamity everywhere for the non-believers… especially for the fighters and supporters of the caliphate in Europe and America."