U.S. activists waging a high-profile campaign against Japan's annual dolphin slaughter and sale of mercury-tainted dolphin meat were snubbed by government officials Friday in Tokyo when they tried to hand over a petition of protest they claim bears 50,000 signatures.

Members of Washington state-based antiwhaling group Sea Shepherd Conservation Society — including well-known Hollywood actress and board member Persia White — said they had planned to hand over the petition at a scheduled meeting at the Ministry of Health, Labor and Welfare's food safety department, but police and guards barred their entry.

"We flew over 5,000 miles to be stood up," said White, who stars in the sitcom "Girlfriends." The activists also tried to meet with the Fisheries Agency but were met with rejection there, the group said.