Ocean Safety officials Monday closed Hanalei Bay to swimmers until further notice after a large tiger shark bit a Kauai surfer’s leg Monday afternoon, according to Kauai County officials.

Lifeguards posted signs and warned beachgoers to stay out of the water. Three tiger sharks — 12- and 15-footers — were spotted a week earlier, on Jan. 28, at Kekaha Beach on Kauai’s west side.

The surfer was reportedly a firefighter, according to a North Shore surf shop owner.

He had been surfing at a spot called The Bowl when he was bitten at around 1:45 p.m.

Medics transported him to Wilcox Medical Center with multiple cuts to his leg, according to Kauai County officials.

Kalina Jones, who works at Hanalei Surf Co., said her boss told her the victim was a firefighter.

Jones, 17, said she had ended her surf session just 20 minutes before the attack.

“It was the first time I was glad I had to come to work,” she said.

She said her boyfriend got out of the water earlier because “he was feeling the sharky vibe.”

Surfer Phil Irons, a Hanalei resident and the father of the late world champion surfer Andy Irons, said heavy rain in Hanalei over the past couple of weeks triggered runoff into the ocean, which attracts sharks.

“Avoid murky water,” he said, adding that he’s seen tiger sharks swim up the Hanalei River.

The Department of Land and Natural Resources, which responded to the incident, cautions beachgoers to avoid murky waters, harbor entrances and stream mouths, especially after heavy rain.

Tiger sharks, considered the most dangerous sharks in Hawaii waters, are often attracted to stream mouths after heavy rain when upland fish and other animals are swept out to sea, according to the DLNR website, which also noted that the greatest number of tiger shark incidents (nine) have occurred between 11:30 a.m. and 3:30 p.m.

A well-known tiger shark attack on Kauai’s north shore involved then-13-year-old Bethany Hamilton, who lost her left arm on Oct. 31, 2003, at Tunnels Beach in Haena.