A 45-year-old Maui diver didn’t immediately realize a shark had bitten him Wednesday afternoon as he was diving in Kaehu Bay. It was the second Hawaii shark attack this week.

He felt it "only when I turned around and saw the fin," Shane Mills, who had recently moved to the area, told Wendy Osher of the website Maui Now.

"It wasn’t like a dog bite or anything," Mills said. "It was more like maybe your cat or something grabbing you."

It was the 11th shark encounter in Maui waters in the past 16 months, and the second in the same general area in just under a year. Statewide, it marked the 21st shark encounter for 2012 and 2013.

Maui County lifeguards and state Department of Land and Natural Resources officers shut down beaches from Sand Piles to Y. Hata store after the attack shortly before 4 p.m.

They will stay closed at least until noon today, when they will assess whether to reopen the beaches.

Firefighters responded to the 3:55 p.m. call to Kukona Place off Waiehu Beach Road, and found Mills already on shore.

Medics treated Mills for some shallow, 3-inch-long cuts to his lower back, then he drove himself to the hospital for follow-up treatment, said Maui Fire Services Chief Lee Mainaga.

Mills described the shark as gray with a white dorsal fin, about 4 to 6 feet long. He said he was in the middle of Kaehu Bay, between Paukukalo and Waiehu, off the mouth of Paukukalo Stream, when he dove down and felt something hit his left upper torso and buttocks, DLNR spokeswoman Deborah Ward said in an email.

Mills, an experienced diver and surfer who works for Scuba Shack, said he was swimming 100 yards offshore in 10 feet of water, looking for octopus and lobster when he felt something grab him, he told Maui Now.

He kicked and elbowed it and swam for shore.

A witness on shore saw the man swim out, saw a splash and saw the man swim back, looking back to see whether the shark followed, but it disappeared, Ward said.

Ocean Safety crews patrolled the water and kept people out of the ocean a mile in each direction of the attack site until sunset Wednesday, and DLNR posted warning signs.

Mills said the water was "a little brown," due to runoff after rain in Upcountry Maui.

Wednesday’s shark attack was one of 11 encounters off Maui since June 26, 2012, according to data at hawaii­sharks.com.

A diver spearfishing at Waiehu was attacked Nov. 4, 2012, and suffered severe lacerations and broken bones to his right leg.

Of the unprecedented number of shark encounters on Maui, nine injured people and two damaged boards.

The most notable was the fatal attack Aug. 14 of a 20-year-old German woman. Visitor Jana Lutteropp died one week after a shark bit off her right arm while she was snorkeling at an area in Makena known as White Rock.

On Sunday, a 25-year-old Kauai surfer and former boxer escaped a shark at Kilauea by punching it eight times and jamming a knuckle in its eye. The shark clamped down on his board and knocked him off.