Islamic authorities in Belgium tried Wednesday to deter young men from going to Syria to fight, saying the Koran provided no justification and that they risked being dangerously radicalised by extremist groups there.
"Their return from the conflict is to be much more feared than their departure," Belgium's leading Islamic groups said in a statement.
"It is to be feared that these young men take on the agendas of the extremist groups they will fight with, which will complicate their relations with fellow European citizens" when they return home, it said.
The document was prepared for discussion in mosques as the issue stirs increasing concern in Belgium, home to a large Islamic community that has seen some 80 youngsters leave to fight in Syria.
It said it was "difficult to find a moral justification for any armed conflict" and to take part, under whatever impulse, "leads to the certain loss of the human spirit."
Khalid Hajii, head of the country's council of Ulemas, Islamic scholars, said the "frustration" of young Muslims played a role but that it would be a mistake to see that as the only cause driving them to take up arms in Syria's bloody conflict, with "indoctrination' a major factor too.
Last month, police cracked down on radical Islamist networks, staging dozens of early morning raids and several arrests of individuals suspected of sending foreign fighters to the Syrian front.
A recent report by King's College London said up to 600 people from 14 European countries, including Austria, Britain, Germany, Spain and Sweden had taken part in the Syria conflict since it began in March 2011.
The largest single contingent was from Britain but based on population, the figures for Belgium, Ireland and the Netherlands were the most significant, with around 200 between them.