MONTEREY, Calif. — Authorities have called off the search for a swimmer who went missing off the coast of California, possibly due to a shark attack.

The individual in question, 55-year-old Erica Fox, was last seen at Lovers Point in Pacific Grove, Monterey Bay, with her disappearance reported shortly after noon on Sunday. This information comes from a joint statement released by the Coast Guard along with the cities of Pacific Grove and Monterey.

Witnesses at the scene provided chilling accounts, with two telling ABC Fresno station KFSN that Fox might have encountered a shark. Another witness relayed to the Coast Guard that they observed a shark with what appeared to be a body in its mouth before it disappeared beneath the waves.

In response to the reports, authorities launched an extensive search operation, deploying both boats and helicopters. The search continued for nearly eight hours on Sunday, extending well into the night. Efforts resumed on Monday morning, but the Coast Guard has since suspended the search, pending any new information or developments.

Boats and helicopters were deployed for Sunday’s search, which lasted nearly eight hours, well past sunset, officials said. The search resumed on Monday morning but was suspended barring any further developments in the case, the Coast Guard said.

The swimmer’s family has been notified, officials said.

Lovers Point Beach in Pacific Grove and McAbee Beach and San Carlos Beach in Monterey are closed through Tuesday, the officials said.

ABC News’ Tristan Maglunog and Amanda Morris contributed to this report.