Greenpeace activists successfully blocked export of Icelandic whale meat to Japan today by chaining themselves to a cargo ship in the Dutch port of Rotterdam, according to dpa. The Nordic arm of the environmental group announced in Copenhagen on Friday that the target of the action, the freighter NYK Orion, was carrying 160 tons of meat harvested from 13 fin whales in Iceland for transport to the Far East. The NYK Line shipping company in Japan eventually relented and unloaded the whale meat in Rotterdam, the harbour police said. The meat containers were handed over to Dutch customs officials. Where they will go from there has to be clarified with their owners and the parties who had signed a contract for the consignment. Police also took into custody seven Greenpeace members who participated in the protest. They were charged with disturbing the peace, but later released. Greenpeace spokesman Martin Norman said his group was satisfied that an attempt to circumvent international whaling bans had failed, but also declared it "bizarre" that the Dutch government had not intervened - leaving Greenpeace with no option but to take action. Iceland has allowed the hunting of fin whales, which can grow up to about 30 meters long, and the smaller minke whales in its waters for several years, despite the existence of a worldwide whaling ban since 1986. The trade in whale meat is also prohibited by the international CITES treaty, which seeks to protect endangered species. Iceland has not ratified the treaty because of its stance on whales. There are few other places outside Japan for Icelandic fishermen to sell whale meat. The Nordic nation admitted in March that smaller consignments had passed through to Latvia and Denmark despite a European Union trade ban. Greenpeace officials argue that Iceland could earn much more money through whale-watching activities. The Icelandic government is nevertheless preparing to allow another 150 fin and minke whales to be shot this summer, according to unofficial reports. Whaling is likely to become a point of contention in forthcoming talks about the accession of Iceland to the European Union.