Failure to parse valid CSS imports with media queries

[cimmanon]

The following is valid CSS:

@import url('sheet-1.css');
@import url('sheet-2.css') screen and (min-width: 300px) and (max-width: 730px);

However, Sass thinks it is an error:

Syntax error: Invalid CSS after \"sheet-2.css') \": expected selector or at-rule, was \"screen and (min...\"\A

Omiting the url() in the Sass file appears to work:

@import 'sheet-1.css';
@import 'sheet-2.css' screen and (min-width: 300px) and (max-width: 730px);

Output:

@import url(sheet-1.css);
@import 'sheet-2.css' screen and (min-width: 300px) and (max-width: 730px);