Olympic tennis seeds announced

The International Tennis Federation has announced the seeds for the London Olympics.

Seedings have been based on ATP and WTA rankings, with Roger Federer topping the men and Victoria Azarenka named the number one woman.

In the men's singles, Novak Djokovic is second, Andy Murray third and David Ferrer fourth following the withdrawal of defending champion Rafael Nadal through injury.

Meanwhile, Agnieszka Radwanska, Maria Sharapova and Serena Williams make up the rest of the top four women.

Bob and Mike Bryan are number one seeds in the men's doubles while Liezel Huber and Lisa Raymond top the women. However, the Williams sisters, who won gold in Beijing, are unseeded.

The draw for the tournament will be made tomorrow.