Police and anti-terrorism investigators have been alerted to the possibility that small groups of ISIS extremists have left Syria for France and Belgium with plans to stage attacks.<br />Belgian intelligence services sent a note to French counterparts about the possible groups, and it was sent to police and anti-terrorism forces across France on Tuesday, a French security official said Wednesday.<br />French authorities remain "very cautious" about the information because they receive such notes routinely, the official said.<br />Belgian officials are cautious too, as the information is believed to be from a single intelligence source and hasn't been confirmed elsewhere.
