How to Remove records from many to many relationship tables in JPA

Hello All, I am getting the constraint violation exception whil deleting the entries

I have Relation tables    TransportationEvent  and Conclusion  , relations like

@Entity
public class TransportationEvent {
...
@ManyToMany(fetch = FetchType.EAGER, cascade = CascadeType.PERSIST)
    private List<Conclusion> conclusions = new ArrayList<Conclusion>();
...
}

@Entity
public class Conclusion {
....
@ManyToMany( fetch = FetchType.LAZY, cascade = CascadeType.PERSIST)
    private List<TransportationEvent> transportationEvents = new ArrayList<TransportationEvent>();
....
}

here in database i have got another two table like
Conclusion_TransportationEvent     and  TransportationEvent_Conclusion
here my requirement is i need to delete  records in both tables (TransportationEvent and Conclusion)
here i am trying to delete conclusion table records like bellow:

removeConclusions(conclusion.getId());
public void removeConclusions(Long id) {
        entityManager = dbConn.getConnection();
        Conclusion conclusion = entityManager.find(Conclusion.class, id);
        entityManager.getTransaction().begin();
        entityManager.remove(conclusion);
        entityManager.getTransaction().commit();
}

but iam getting constraint violation error . 
Caused by: java.sql.SQLException: The DELETE statement conflicted with the REFERENCE constraint "FK30CDAB072AAE439". The conflict occurred in database "ECT", table "dbo.TransportationEvent_Conclusion", column 'conclusions_id'

by searching some forums i got syntax like

@Cascade(org.hibernate.annotations.CascadeType.DELETE_ORPHAN)   and i applied that as

@ManyToMany(fetch = FetchType.EAGER, cascade = {CascadeType.PERSIST, CascadeType.REMOVE})
    @Cascade(org.hibernate.annotations.CascadeType.DELETE_ORPHAN)
    private List<Conclusion> conclusions = new ArrayList<Conclusion>();

@ManyToMany( fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    @Cascade(org.hibernate.annotations.CascadeType.DELETE_ORPHAN)
    private List<TransportationEvent> transportationEvents = new ArrayList<TransportationEvent>();

in both entities even though iam geting same constraint violation
can some one help me how exactly i need to use this to delete the records from Conclusion and TransportationEvent.

Thanks in advance!

Please post the exception full stack trace.