Prince William County police will begin enforcing a crackdown on illegal immigrants next week.

The entire 530-member police force is amid training to understand their new duties under the policy, which was put in place by the county's board of supervisors.

The new policy that takes effect Monday has received national attention as one of the most aggressive in the United States. It directs police to check the immigration status of anyone who is detained if the officer has probable cause to believe the person is an illegal immigrant.

Opponents of the measure say that despite police assurances, the policy will lead to racial profiling.