A civic group held a protest in central Seoul on Wednesday against Japan's claim to a set of disputed islets lying halfway between the two neighbors.
Demonstrators called for a boycott of Japanese goods including cigarettes in protest against Japan's persistent claim to the islets, known as Dokdo in South Korea and Takeshima in Japan.
The protesters chanted anti-Japan slogans and held placards, some of which read: "Boycott Mild Seven for Dokdo."
In a bid to show their resolve, they set fire to mock-up Japanese products.
South Korea's territorial dispute with Japan over the rocky islets has worsened recently with an attempt by three Japanese lawmakers of the Liberal Democratic Party to visit South Korea's Ulleung Island, the nearest inhabited island to the disputed islets. They were denied entry.