(CNN) -- A cap and goggles belonging to a 63-year-old woman presumed to have been "taken" by a large shark while swimming off the coast of Australia have been found, along with human remains, police said Friday.
The search for Christine Armstrong was ongoing Friday morning, New South Wales Police said in a statement.
Armstrong was swimming Thursday with a group of friends off a beach in Tathra in New South Wales when she complained and headed back to shore, Police Inspector Jason Edmunds said.
The rest of the group, including her husband, later saw a shark, estimated to be about 11 feet long, swimming near them, causing them to bunch together for safety.
They swam back to the beach club, but found no trace that Armstrong made it back.
Edmunds said that another witness on some nearby rocks spotted a large shark attacking something in the water roughly 150 yards offshore, which he believed to be a swimmer.
The remains and swim cap and goggles were found late Thursday. The remains will undergo forensic testing, police said. Results are not expected for "several weeks."
The popular beach is now closed for a safety assessment, but an extensive search of the area failed to find Armstrong or signs of the shark.
"The community is in shock, and the husband is taking it hard, as he has been with her since they were kids," said Edmunds, noting that sightings of large sharks are rare, and he couldn't remember any other attack in the area.
"Cancer, heart attacks -- those are all things we fear but expect, but who gets taken by a shark?"
It is believed the woman was a lifeguard herself, according to a post on the Surf Life Saving New South Wales website. The other lifeguards she was swimming with are receiving counseling, the post said.