Adwords Api add Placement

[carlos....@cuatroochenta.com]

Where are using php's adwords api in order to create and manage campaigns.

We can add some placements, 

foreach ($adGroupAdwordsIds as $adGroupAdwordsId) {
    // Placements
    $placement = new Placement();
    $placement->setUrl($url);
    $criteria[] = $placement;

    $placementCriterion = new BiddableAdGroupCriterion();
    $placementCriterion->setAdGroupId($adGroupAdwordsId);
    $placementCriterion->setCriterion($placement);

    // Create an ad group criterion operation and add it to the list.
    $placementCriterionOperation = new AdGroupCriterionOperation();
    $placementCriterionOperation->setOperand($placementCriterion);
    $placementCriterionOperation->setOperator(Operator::ADD);
    $operations[] = $placementCriterionOperation;
}
$aux = $adGroupService->mutate($operations); // ->getValue[0];

But when we check the Adwords account we see that the placements have been inserted as "observations" instead of "targets" so the campaign is not well segmeneted.

How can we achive this and  add those placements as "targets"?

Thanks.

Regards