In Symfony2, can the validation.yml file be split into multiple files using imports?

Right now, I have a file called validation.yml with the validation of all the bundle's entities in one file.

validation.yml

Blogger\BlogBundle\Entity\Comment
    properties:
        username:
            - NotBlank:
                message: You must enter your name
            - MaxLength: 50
        comment:
            - NotBlank:
                message: You must enter a comment
            - MinLength: 50

Blogger\BlogBundle\Entity\Enquiry:
    properties:
        name:
            - NotBlank: ~
        email:
            - Email:
                message: symblog does not like invalid emails. Give me a real one!
        subject:
            - NotBlank: ~
            - MaxLength: 50
        body:
            - MinLength: 50

But I'd like to split it into two files and import them both. This is what I tried and it didn't work:

validation.yml

imports:
    - { resource: comment.yml }
    - { resource: enquiry.yml }

comment.yml

Blogger\BlogBundle\Entity\Comment
    properties:
        username:
            - NotBlank:
                message: You must enter your name
            - MaxLength: 50
        comment:
            - NotBlank:
                message: You must enter a comment
            - MinLength: 50

enquiry.yml

Blogger\BlogBundle\Entity\Enquiry:
    properties:
        name:
            - NotBlank: ~
        email:
            - Email:
                message: symblog does not like invalid emails. Give me a real one!
        subject:
            - NotBlank: ~
            - MaxLength: 50
        body:
            - MinLength: 50