Police found "traces" of a plot to launch a new attack in Belgium when they arrested four people suspected of recruiting jihadists for Syria and Libya, prosecutors said Wednesday.

The four were charged with "participating in the activities of a terrorist group" following their arrests in the northern port of Antwerp and other Flemish-speaking cities, the federal prosecutor's office said.
"The four were more involved in the part of recruiting," Eric Van der Sypt, a spokesman for Belgium's federal prosecutors, told AFP. "And we found traces of plans for an attack in Belgium."
He said the probe into an alleged plot continued while his office said that "for now there is no link" with the investigation into the deadly March 22 bombings in the capital Brussels.
The prosecutor's office said the four people arrested are "suspected of having wanted to recruit people to send them to conflict zones in Syria and Libya," adding that some of them had intended to travel to those areas and join the Islamic State group.
Eight raids in Antwerp as well as in Ternat and Borgerhout turned up neither weapons nor explosives, the statement said without saying when the action was carried out.
The investigating judge ordered one of the four to be detained, but released the three others -- one on condition he wear an electronic bracelet and the other two under "strict" conditions, it added.
Belgium is still reeling from the Islamic State suicide bomber attacks at Brussels airport and on the metro on March 22 which killed 32 people and wounded hundreds more.
They came five months after jihadists, many of them from Brussels, carried out gun and bombing attacks in Paris on November 13, killing 130 people and wounding hundreds more.
The Paris and Brussels attacks have both been linked to the same jihadist cell with links to IS in Syria.
Per capita, Belgium has produced the highest number of so-called foreign fighters in the EU who have travelled to wage jihad in Syria and Iraq, an estimated 500.