"We are very disappointed by Laurent's actions, which are against our clear instructions".
Koscielny has been left out of Arsenal's squad that travelled to the United States for their pre-season tour after he refused to be part of the travelling party.
'We hope to resolve this matter and will not be providing any further comment at this time'.
The Gunners are believed to value Koscielny at €10m but the French club do not want to pay such a fee for the 33-year-old defender.
In a statement released shortly after the incident, Arsenal said: "We are working closely with Bochum and Jordi and we are giving him our full support".
The north Londoners' latest bid is an improvement on their original offer for the 18-year-old defender, amid suggestions that Tottenham were also ready to enter the race.
This decision from Koscielny will no doubt have a huge impact on the locker room.
Arsenal were also keen to keep him, so they came back with an offer of a new two-year contract to be signed this summer.
It's not a good start to the new season preparations for Arsenal manager Unai Emery who's bidding to improve on last term's fifth placed finish in his second season at the Emirates Stadium. They now need to move quicker regardless of how this situation turns out.
Koscielny subsequently became club captain under former boss Arsene Wenger.
Reports suggest Emery has a transfer budget of just £45m this summer, meaning he must sell to finance his key targets. Then again, you can not let one player dictate your transfer dealings as they sets a poor precedent.