Multiple news outlets reported on Thursday that an unknown poster on the Chinese website Baidu.com directed a death threat at tennis star Roger Federer.

According to the AFP, the poster, using the screen name "Blue Cat Polytheistic Religion Founder 07," wrote, "On October 6, I plan to assassinate Federer for the purpose of tennis extermination."

Federer and his family are in town for the Shanghai Masters, an annual tournament.

The Baidu user "also posted a doctored photo of a decapitated Federer on his knees on a tennis court with a masked executioner dressed in black and holding an axe next to him," AFP reported.

In response, Shanghai police are increasing security, according to the Shanghai Youth Daily.

We hope that it was an oral threat only, and the fan won't take substantive action. However, we have to take it seriously," Yang Yibin was quoted as saying.

As Sports Illustrated notes, tennis-court security has been a hot topic in the sport since Monica Seles, then the world's top-ranked women's player, was stabbed by a deranged fan of her rival, Steffi Graf, during a match in 1993.

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