Better check your Facebook settings before posting a party invitation online.

A teenage girl in Germany who forgot to mark her birthday invitation as private on Facebook fled her own party when more than 1,500 guests showed up and around 100 police officers, some on horses, were needed to keep the crowd under control.

Eleven people were temporarily detained, one police officer was injured, dozens of girls wearing flip-flops cut their feet on broken glass and firefighters had to extinguish two small fires at the 16th birthday party in Hamburg, police spokesman Mirko Streiber said Sunday.

The birthday girl, identified only as Thessa, went into hiding, Streiber said, but "nonetheless the party was a hit."

Thessa had initially only wanted to ask some friends over to her home in Hamburg-Bramfeld when she posted her invitation on Facebook, but mistakenly she published it so that everyone on Facebook could see it.

The invitation quickly went viral, and some 15,000 people confirmed online they would come to the party