Hyderabad, Aug 12 - Two Austrian players have pulled out of the World Badminton Championships and quietly left the city without informing the organisers.

The players, Juargen Koch and Peter Zauner, are surmised to have feared security threat and swine flu.

A Badminton World Federation (BWF) official told IANS that the two players have indeed left Tuesday evening without giving any reason.

'We are assuming that it's a combination of factors since they have not go in touch with us. We got to know from the team officials. It's their call and we couldn't have done much,' the official said on the condition of anonymity.