Lusaka -Zambian police officers have been warned that it is illegal for them to marry foreigners, officials said on Thursday, in a crackdown over national security.The move to strictly enforce long-established wedding regulations attracted criticism from human rights' groups that described it as discrimination.The police force said that increasing numbers of officers were getting married to foreigners in defiance of the law."What prompted us to say that officers should not marry foreigners is because there are officers who are breaching the law," police spokesperson Esther Katongo told AFP."Issues of security are delicate and we cannot just sit and watch men in uniforms marrying women from foreign countries."Katongo declined to identify the nationalities of the foreigners, but some local cases have involved marriages to Rwandans, according to AFP reporters.In an internal memo this month, inspector general of police Kakoma Kanganja ordered that the law over police marriages had to be obeyed.He said that all foreign marriages must be declared within one week or officers would face disciplinary actions.But the constitutionally mandated Human Rights Commission said that the law was discriminatory and should be repealed."We believe in globalisation and this order is not sitting well with human rights," said commission spokesperson Mwelwa Muleya."It's a prejudiced position against people. It is discriminatory and it is our hope that the police will review this order. It might have served a purpose at some point but not now."Zambia is a relatively stable and peaceful country, though elections last year were criticised for violence during the campaign and muzzling of the media.