Arsenal have had a dig at Tottenham's lack of recent success - via the unusual route of their online shop.
The Gunners' north London rivals have had a hard time winning any trophies in recent years, last lifting the League Cup in 2008.
It has been almost 31 years since they last won the FA Cup and they have not been crowned champions of England since they won the First Division in 1961.
What has happened?
Arsenal have poked some fun at their local foes by displaying a cheeky message when fans browse their shop.
ArsenalAny attempt to checkout without adding anything to the shopping cart is met with a message that reads: "Your basket is as empty as Tottenham's trophy cabinet."
What has been said?
Arsenal have said that the message had not been officially approved to appear on their site and would be removed.
An official statement from the club read: "This was posted to the site in error without appropriate checks and approvals and is being removed as quickly as possible."
When did Arsenal last win a trophy?
While Arsenal have had a few rough years recently, they have been much more successful than Spurs.
The Gunners have won the English top-flight 13 times, though the most recent occasion was in 2004.
They have had more success in the FA Cup recently, winning it in 2020 for the 14th time to make them the competition's most successful team.
Mikel Arteta's men currently have bragging rights over Tottenham after beating them 3-1 in the latest North London Derby this season.
The two teams are level on points in the Premier League with Arsenal holding a superior goal difference, but Spurs have a game in hand.
