Two-time Wimbledon champion Petra Kvitova has been injured by a knife-wielding attacker at her home during an apparent burglary.

The 26-year-old tennis star tweeted her left hand has been "badly injured" as she tried to defend herself.

She added: "I am shaken, but fortunate to be alive.

"The injury is severe and I will need to see specialists.

"But if you know anything about me I am strong and I will fight this. Thank you again for your love and support."

The incident happened on Tuesday morning in the eastern Czech town of Prostejov.

It came as Kvitova withdrew from the Czech Republic team at next month's Hopman Cup because of an earlier foot injury.