Johannesburg - Violent behaviour from fans would not be condoned at Loftus Versfeld, the Blue Bulls Company said on Sunday after a scuffle broke out and a man was arrested in Pretoria.
Shortly after the final whistle in the Bulls' 29-23 loss to the Blues on Saturday night, Johannes Gideon Nel dodged security and threw a plastic bottle at the players, the Pretoria franchise said in a statement.
Nel struck Blues captain Keven Mealamu.
"We absolutely refuse to accept this unsportsmanlike behaviour and have arrested the individual," said Blue Bulls Company chief executive Barend van Graan.
"The Blue Bulls Company works tirelessly to create an environment that is friendly and fair to all ages, races and nationalities.
"We want to warn our fans that irrespective of our on-field performances, we will not accept 'fans' taking out their anger on our opponents."
The Blue Bulls said a charge of assault had been laid at the Sunnyside police station.
"We will continue to enforce even stricter security measures as behaviour like this is not welcome at Loftus," Van Graan said.
The touring Blues side had accepted an apology from the Blue Bulls for the spectator's behaviour, Van Graan said.