A 66-year-old Washington state woman was injured in a suspected shark attack Friday morning in waters off Charley Young Beach in Kihei.

Maui County Fire Serv-ices Chief Edward Taomoto said the woman sustained injuries to her lower leg and was transported to Maui Memorial Medical Center in serious condition.

The attack occurred shortly before 10 a.m.

The woman, a part-time Kihei resident, had been snorkeling in waters about 40 feet from the shore at a depth of 7 feet when the attack occurred, according to a state Department of Land and Natural Resources news release.

A nearby stand-up paddleboarder heard the woman yell and came over to help. The paddler pulled the woman onto the board and brought her to shore. A visitor from Washington state also swam out to assist her.

Two nurses and a firefighter from the mainland who were on vacation treated the woman on the beach before lifeguards arrived, according to a Maui County Fire Department news release.

There were no witnesses to confirm a shark sighting, but the woman’s injuries are consistent with those of a shark bite, officials said. Ocean conditions at the time of the attack were described as calm but “somewhat murky,” according to the DLNR release.

Lifeguards patrolled waters by jet ski to warn ocean users about the incident. Also on the scene were staff members with DLNR’s Division of Conservation and Resources Enforcement and Division of Aquatic Resources.

Shark warning signs were posted along the coastline from Kalama Park to Kamaole Beach Park III. Signs will remain posted until noon today, when waters will be reassessed.

According to the state’s records on shark incidents in Hawaii waters, Friday’s incident marks the fifth apparent attack on Maui this year.

>> Aug. 6 — A stand-up paddleboarder was about a mile off of Hamakuapoko Beach in Paia when a tiger shark, estimated at 10 feet long, bit the paddleboard’s hydrofoil. No injury was reported.

>> May 3 — A swimmer was floating in waters about 40 yards from the shore at Wailea Beach when a shark attacked. The swimmer suffered minor lacerations to the right shoulder. The length and species of the shark was unknown.

>> March 3 — A snorkeler was about 450 yards off of Olowalu Beach when an 8-foot tiger shark attacked. The snorkeler suffered minor lacerations to her left foot.

>> Jan. 23 — A stand-up paddleboarder was about 150 to 200 yards off of Wailea Beach when a 10- to 12-foot tiger shark bit the tail of the board. The paddler was uninjured.

Earlier this month the state warned beachgoers to exercise caution in Hawaii waters because the number of shark attacks tends to increase during October.

From 1980 through 2015, officials recorded 122 instances of unprovoked shark bites in Hawaii waters. Of that tally, 26 occurred during October. In 2015 three of seven shark attacks in Hawaii occurred in October.

Researchers maintain that a possible explanation is that there are simply more sharks in Hawaii waters in the fall. Approximately 25 percent of female tiger sharks in the Northwestern Hawaiian Islands migrate to the main islands during that time period to give birth.

More sharks in near-shore waters coupled with the need for pregnant sharks to feed might increase the chance of an attack on a human.