Firms scrambling to take advantage of strong anti-Japan fervour are warned not to push the sentiment too far In the top right corner of the television screen, against a video of a madly gyrating pop singer, a cartoon caricature of a rocky grey island topped by the South Korean flag fades in and out of view, along with the slogan 'Tokdo, our land'. A local music channel with a main audience of teenagers is an unlikely place to air political messages. But South Korean broadcaster M.net is one of dozens of businesses that have thrown their weight behind Seoul's claim to the Tokdo islands. An uneasy disagreement over the volcanic outcrop, which is known in Japan as Takeshima, exploded into angry exchanges last week after Japan's Shimane prefecture passed a law designating February 22 'Takeshima Day', in recognition of the day in 1905 when the assembly declared its ownership of the islands. The law incited a wave of nationalistic fervour in South Korea, and industry has been scrambling to take advantage of the strong public sentiment. Telephone networks have been offering customers the opportunity to donate a percentage of their bills to groups supporting South Korea's claim to the island. Another has been distributing small phone accessories in the shape of the contested islands. But with almost US$70 billion in two-way trade between South Korea and Japan, critics have accused some companies of going too far in trying to exploit the anti-Japanese feeling generated by the territorial row. Janssen, maker of the painkiller Tylenol, was forced to withdraw an ad that used the image of Tokdo-Takeshima alongside the catchline: 'They claim Tokdo as their territory. It caused a headache for 48 million Koreans. Your headache over such a ridiculous claim means you love your country.' President Roh Moo-hyun has stoked the rhetoric by confirming in a letter addressed to his people that South Korea is ready for 'diplomatic war' with Tokyo. 'We cannot sit back and watch Japan justify its history of aggression and colonisation, and pursue hegemonic power again,' he wrote. Mr Roh's senior secretary for public relations, Cho Ki-suk, said: 'In the past, when Japanese made statements justifying past aggression, the government's position was to remain silent. 'Now, he will not avoid confrontation.' South Koreans are often noted for their fierce nationalism, and the present public mood has been compared to the anti-US fury that swept the country three years ago after the accidental deaths of two Korean schoolgirls hit by a US military vehicle, which sparked mass protests. But even the local press - key ralliers of nationalist sentiment - have been taken aback by Mr Roh's remarks. 'This is the time for the government to appeal for calm, reasonable behaviour from the people,' the influential Joongang Ilbo editorialised on Thursday. Asked if the president's statements were not too strong, Mr Cho conceded: 'I think people [like the president and myself] have to be more careful in the kind of expressions we use,' but warned, 'this could be the start of a conflict'. Calls for calm have come from unlikely spokesmen. South Korean actor Bae Yong-joon, who has a huge following among female audiences in Japan, has been balancing his fan base against domestic criticism that he had earlier failed to back South Korea's claim to the disputed territory. 'Tokdo is Korean territory, and therefore Korean people should take a more rational approach to the issue,' he said in a message posted in Korean at his website. 'I genuinely hope both the Korean and Japanese people will not become involved in emotional conflict that puts the relations between them in jeopardy.'