Belgium's federal prosecutor told reporters that a Daesh flag was found next to the body of a suspect shot dead during an operation on Tuesday.
Thierry Werts described the suspect as a man of Algerian origin who is known to police for a previous theft offence.
Also found next to his body was what Werts said was a Salafist manual. That's the ideology to which Daesh subscribes.
Police were fired on as they carried out a routine search in the Forest area of Brussels. Four officers were wounded in the shootout.
The joint Belgian-French operation in Brussels is linked to November's Paris attacks, and is ongoing.
Two suspects are still being hunted by police, said Werts.
