Greeted by cheers from a small group of anti-whaling supporters, a Greenpeace boat docked in Japan on Friday, ending a weeklong standoff with Japanese authorities who had effectively barred their entry into port.

But the arrival of the Dutch-flagged Esperanza at Yokohama port, southwest of Tokyo, was strictly guarded by port authorities wary of the ship for its role in tracking Japan's latest whaling mission in the Antarctic.

Japanese officials have called Greenpeace activists terrorists and threatened legal action against environmental groups that harass whaling boats.

Following a week of negotiations, Esperanza has been allowed two days in Japan to restock supplies and change its crew. But Yokohama city turned down a Greenpeace request to put the ship on show to the public, according to Nobuhiro Kinoshita of the city's Port and Harbor Bureau.

The ship's arrival in Japan also was delayed after the country's seamen's union demanded that the ship's shipping agent not deal with the environmental group, prompting the agent to cancel the job.

"We're disappointed that we're still treated here as bad people," said Luke Cordingley, a British crew member who spent months tracking the fleet of Japanese whaling ships off the Antarctic. "All we want is to open a dialogue with the Japanese people."

Tokyo has been especially sensitive to criticism over its annual whaling hunt off Antarctica after its latest mission was cut short by a ship fire that left one crew member dead. It was the first time in 20 years that Japan had to abort its whaling mission.

Though the blaze on the processing vessel, Nisshin Maru, has not been linked to earlier high seas demonstrations by activists, whaling officials have blasted environmental groups for interfering with the hunt.

Japanese video showed protesters aboard the ship of another anti-whaling group, the Sea Shepherd, launching smoke canisters and dropping nets to entangle the whaling ships' propellors.

Greenpeace has said it had nothing to do with the attacks and offered the Nisshin Maru assistance at the time, providing the whaling fleet with information on surrounding ice conditions. The Japanese, however, declined an offer by Esperanza to tow the Nisshin Maru out of the area after the fire.

Japan's fleet is part of a scientific whaling program that Tokyo says provides crucial data for the International Whaling Commission on populations, feeding habits and distribution of the mammals in the seas near Antarctica.

The hunts are allowed by the International Whaling Commission, but environmental groups have long condemned the hunts as a pretext for keeping commercial whaling alive after the practice was banned by the IWC in 1986.

The Nisshin Maru returned to port from Antarctica last month with a catch of 508 whales out of a target of 860. Leftover meat from Japan's research program ends up on the market, though whale meat is increasingly out of fashion in Japan, leading to an unprecedented glut and plunging prices.