"Sharks can bite hard," says surfer Kiowa Gatewood, from his hospital bed in Hawaii, after a vicious tiger shark attack in murky waters churned up by Tropical Storm Flossie. KNHL's Tim Sakahara reports.

The second shark attack in four days has forced the closure of two beaches on the Hawaii island of Maui, officials said Wednesday.

A woman was bitten as she enjoyed an early morning swim about 30 feet from the shore of the rocky point at Ulua Beach Park on Maui at around 8:30 a.m.

Clarence Yamamoto, Maui chief for The Department of Land and Natural Resources (DLNR) would not reveal the extent of her injuries, but told The Maui News that she had been able to swim to shore after the attack.

She was bitten in her upper torso according to NBC affiliate in Honolulu, KHNL.

Yamamoto added that there had been “limited visibility” in the water and the woman had been unable to identify the species of shark.

In response, authorities then closed the beaches from Polo Beach Park to the Mana Kai Maui Resort in the Kihei-Wailea area.

Officials will evaluate Thursday whether it is safe to reopen them.

The attack was the second in just three days off the Hawaiian islands.

Kiowa Gatewood was surfing off Oahu’s White Plains Beach, Sunday afternoon, when he spotted, what he thinks was a Tiger Shark.

“I was sitting on my board, when all of a sudden I saw this shark come out of the water and grab my leg,” the 19-year-old told KHNL, Monday.

“From there, I had this instinct to like, hit it with my left hand and then it let go and turned around and swam away.”

He underwent surgery on his left knee and upper calf and has now started rehab.

"Sharks can bite hard," he said, but he added that he plans to surf again.

According to the website Hawaiisharks.com, there have been nine shark attacks off Maui within the past year.