(INSIDE EDITION) -- A popular aquatic park in San Francisco has been closed after three people were attacked by aggressive sea lions, officials said.

Three swimmers were bitten in the same week, two of which in a 24-hour period between Thursday and Friday, authorities said.

Christian Einfeldt, 56, said he encountered a 400-pound sea lion that bit him in the arm on Thursday.

“I turned around and I saw a large male bull sea lion [a few feet away], and I became very concerned,” Einfeldt told KTVU News.

The lawyer, who has been swimming the cove for two years, said he shouted “No!” but the animal kept coming.

“His head kind of actually slid down my arm because he was still coming forward,” he added. “Fortunately he only got one tooth into my arm.”

Einfeldt was rescued by a sailboat and rushed to a nearby hospital, where he underwent two surgeries and has received shots in case the sea lion has rabies.

Less than 24 hours later, Rick Mulvihill was bitten in the groin area. He was rushed to the hospital with a severe bite, a fire department official told the San Francisco Chronicle.

An unnamed swimmer was also bitten earlier in the week, but did not require treatment.

Officials said it was unclear whether the same animal was responsible for all of the attacks.

“It’s really hard to speculate why this interaction happened,” Shawn Johnson, the director of veterinary science at California’s nonprofit Marine Mammal Center, told KTVU. “But any time you’re interacting with a wild animal, there’s a possibility of getting bit.”

Authorities said the cove would be closed through Monday as a safety plan is developed.