William sisters withdraw from doubles at Australian Open

Serena and Venus Williams have pulled out of women's doubles at the Australian Open, where they've won four titles.

The Williams sisters were scheduled to play their first-round match Wednesday against Anabel Medina Garrigues of Spain and Yaroslava Shvedova of Kazakhstan.

A tournament official confirmed the Williams sisters had withdrawn but did not specify a reason.

Both sisters won their first-round singles matches in singles on Tuesday.