An 18-foot minke whale ran aground on a sandbar in the Amazon jungle some 1,000 miles from the ocean, Brazilian media reported Friday.

Globo television broadcast images of dozens of people gathered along the Tapajos River splashing water on the animal, whose back and dorsal fin were exposed to the hot Amazon sun. Sea creatures rarely venture so far into fresh water.

"It apparently got separated from its group and swam upstream," biologist Fabio Luna said in a televised interview from the site. "It's very unusual."

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Scientists said the whale was 18 feet long and weighed about 12 tons, and were working to dislodge the mammal and return it to the ocean.

The whale ran aground Wednesday near Santarem in Para state, Brazil's Environmental Protection Agency said, according to the Globo newspaper.

Phone calls to the agency went unanswered Friday, when many government offices were closed for a long holiday weekend.

The creature reportedly is a minke whale, the second smallest of the baleen whales after the pygmy right whale, with an average length of about 23 feet.

The International Whaling Commission Scientific Committee estimates there are about 184,000 minke whales in the central and northeast Atlantic Ocean.