Japanese whalers brought ashore their first catches on Monday as the country resumed commercial hunting after a hiatus of more than three decades - a move that has aroused international condemnation.

Five vessels set sail under grey morning skies from northern Japan's Kushiro with their horns blaring and grey tarps thrown over their harpoons. By Monday afternoon they were back with their catch: two grey minke whales.

The hunts come after Japan decided to withdraw from the International Whaling Commission, a move slammed by activists and anti-whaling countries but welcomed by Japanese whaling communities.

"Today is the best day," said Yoshifumi Kai, head of the Japan Small-Type Whaling Association, as the ocean giants were hauled ashore.

"It was worth waiting for 31 years," he said with a smile.

One of the whales, more than eight metres (27 feet) long, was hoisted from a ship onto a truck and driven to a warehouse.