Anchor in URL when using Symfony's redirect function

I'm using

$this->redirect('route', array('id' => $id));

but I need to be able to put "#" anchor at the end but I can't find a way of doing that. Any ideas?

The code

$this->redirect('route', array('id' => $id));

returns /route/id/5 but I want to be able to create /route/id/5#anchor7

Solution

$this->redirect($this->generateUrl('route', array('id' => $id)) . '#anchor7');

UPDATE:

In Symfony 3.2 you can do this:

// generating a URL with a fragment (/settings#password)
$this->redirectToRoute('user_settings', ['_fragment' => 'password']);