Environmental activists in Seattle paddled out to sea to protest a Shell oil rig moored off the coast of the US city that is headed for Arctic drilling, local media reported.

Hundreds of kayaks, canoes, sailboats and a solar-powered barge called "The People's Platform" circled around Shell's massive yellow and white oil rig moored in the city's port, The Seattle Times reported.

Protesters held signs reading "Paddle in Seattle" and posted flags from their boats calling for "Climate Justice," condemning Shell's plans to drill in the Arctic.

The protest follows an announcement from President Barack Obama this month allowing Shell to drill in the Arctic, a move that has angered environmentalists.

"The tiny boats on the water against the backdrop of the giant oil rig... It is a chance to show how much people care," protester Amy McKendry told the newspaper.

The 307-foot (94-meter) Shell oil rig has been in Seattle port since Thursday, according to The Seattle Times.

The rig is the largest part of the 25-vessel fleet Shell Oil has in the area as it prepares to resume oil exploration in Alaska's Arctic, the newspapaper added.

Obama recently called oil production "important," while also asking for a transition towards cleaner energy.

Environmental groups oppose the drilling in part because of the threat an oil spill would pose to the region full of vulnerable Arctic animals.

Shell put its drilling plans for the Alaskan Arctic on hold in 2013 following multiple problems with two exploration rigs.