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Story by The Associated Press

The U.S. Coast Guard detained several protesters in kayaks who formed a blockade Monday to try to stop Royal Dutch Shell’s drill rig as it left Seattle on its way to explore for oil in the Arctic Ocean.

Several people were taken into custody, mostly for violating the safety zone around the vessel, Coast Guard Lt. Dana Warr said. The agency did not immediately have a number, but Greenpeace says 13 were detained.

About a dozen “kayaktivists” paddled out around 4 a.m. and tried to prevent the massive 400-foot long rig from leaving, said Cassady Sharp, a spokeswoman for the environmental group. Several dozen supporters in kayaks and canoes lined up behind them, she said.

Seattle Councilman Mike O’Brien was among those scooped up from their kayaks. He and others paddled into Seattle’s picturesque Elliott Bay before dawn to oppose Shell’s plans to open a new frontier of fossil fuel exploration off Alaska’s coast.

“That monstrous rig is headed to the Arctic to attempt to do something unconscionable,” he said in a text message while being processed by the Coast Guard at its offices. “I had done everything I know how to do as a citizen, an activist, and as a councilmember to stop Shell from drilling in the Arctic.”

O’Brien said he knew the action comes with risks, but “that is nothing compared to the climate risks to billions of lives if Shell is successful in drilling Arctic oil.”

The petroleum giant has been using the port to load drilling rigs and a fleet of support vessels with supplies and personnel before spending the brief Arctic summer in the Chukchi Sea, which stretches north from the Bering Strait between Alaska and Russia.

Shell spokesman Curtis Smith said Monday that the vessels are on the way to Alaska.

“We remain committed to operating in a safe, environmentally responsible manner and look forward to exploring our Chukchi leases in the weeks to come,” he said in an email.

The Coast Guard said the protesters were not arrested. Some may be issued notices of violation, Warr said.

Monday’s blockade was the latest in a string of protests since the Polar Pioneer arrived in Seattle in May. Activists say they are concerned about the risks of an oil spill in the remote Arctic waters and the effects that tapping new oil and gas reserves will have on global warming.

Activists also have chained themselves twice to a support ship in Bellingham, north of Seattle. They have tried to block entrances to the Seattle terminal where the rig was loaded. Several have been arrested.

Officials in Alaska, including the governor, have touted the economic benefits that drilling could bring there and to the Pacific Northwest.

The U.S. Geological Survey estimates Arctic offshore reserves at 26 billion barrels of recoverable oil and 130 trillion cubic feet of natural gas. Shell says developing these reserves could increase domestic oil supplies by more than 1 million barrels a day.