Girl, 11, arrested over robbery attempt

Three girls including an 11-year-old are in police custody after allegedly attempting to rob two teenagers with a box-cutter in central Brisbane.

Police say the trio, two of them 14 and the other 11, approached a 17-year-old girl and a 13-year-old girl near the Queensland State Art Gallery at South and demanded money.

When the victims said they had none, one of the girls pulled out a box cutter and threatened them.

The trio was arrested an hour later and are being questioned.