c# how to read xml attributes with xelement

I have a XML with this string:

<media:thumbnail xmlns:media="http://search.yahoo.com/mrss/" url="http://3.bp.blogspot.com/-tMQm4zsM-Yg/TdFEfG2y7GI/AAAAAAAAAT0/XGyQ8vFdVwY/s72-c/moorea-view.jpg" height="72" width="72" />

how can I read the attribute "url" with XElement?