French media have reported that the man arrested over the Jewish Museum shootings in Brussels, was suspected of having visited jihadist groups in Syria in 2013.
Joel Rubinfeld, head of the Belgian League against Antisemitism, told of their concerns over the Syrian visit:
This is a relief.
But this is also worrying us ... it is is crucial that countries who have citizens who have gone to Syria, take all necessary measures to make sure this does not happen again.
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Labour strongholds tended to remain so - apart from a major loss for the party in Dudley.
Labour suffered a "terrible" defeat in Rhondda but has already won 16 Welsh Assembly seats as it looks to record a fifth term in office.
UKIP have made further gains in the local elections in the Anglia region and the Conservatives have won back control in Peterborough.