The historic rivalry between Peru and Chile has spilled into cyberspace with hackers from both countries striking at government websites.
The two countries are now trying to reconfigure their websites
They have been posting nationalistic claims to a disputed maritime area, seafood and a drink called pisco.
In the latest attack, the Peruvian judiciary's web page was targeted by a suspected Chilean hacker.
Chile and Peru are currently embroiled in a diplomatic dispute over fishing waters in the Pacific Ocean.
Peru is claiming a 37,900 sq km (14,600 sq miles) area that is currently under Chile's control.
In the past, Chileans and Peruvians have also argued over the rights to Pisco, an alcoholic drink which Peru claims as its own but is trademarked, produced and marketed in greater volume by Chile.
They have even rowed over whose seafood is better.
'What is our'
The Peruvian authorities said the suspected Chilean hacker posted several anti-Peru messages on the country's judiciary website.
One read: "We fight for what is ours. The ocean and pisco are Chilean!". There were also insults directed at Peruvians in general.
Peru believes the attack was a counter-strike after a Peruvian hacker known as Cyber Alexis allegedly broke into the Chilean National Emergency Office's site.
Media reports say Cyber Alexis posted missives proclaiming: "We do as we like with our policy and our ocean" and "Nobody can match ceviche (citrus-cured fish) and pisco, or equal their quality".
Both countries are now trying to reconfigure their websites to avoid future attacks. On Thursday, the Chilean website was still displaying a sign that it was "under maintenance".
Peru and Chile have a history of border disputes dating back to the 19th Century.
Chile fought the War of the Pacific against Peru and Bolivia from 1879 to 1883, winning Bolivia's outlet to the sea and extensive areas from Peru.