Emergency responders were searching late Sunday for swimmer who may have been attacked by a shark at Wildcat Beach in Northern California, officials said.

The Coast Guard received a report at around 10:40 a.m. that a person appeared to have been attacked by a shark at Point Reyes National Seashore in Marin County.

The person may have been pulled under the water, officials said.

"The search continues for a missing person last seen in the water at Wildcat Beach this morning," the Point Reyes division of the National Park Service said on social media in the evening.

Crews from the park service were joined in their search by Marin County and Stinson Beach fire staff, which had brought fire engines and all-terrain vehicles, officials said. A U.S. Coast Guard helicopter and cutter were also on the scene.