(CNN) -- A man who suffered lacerations to his legs while in the water at a Massachusetts beach Monday apparently was bitten by a shark, authorities said.
"It looked like a shark bite to me," Truro, Massachusetts, Fire Chief Brian Davis said of the incident at nearby Ballston Beach. "Witnesses said they saw (a) fin. They saw him go under water. He was hollering for help."
The man suffered non-life-threatening injuries on the lower part of both legs, Davis said. The man was conscious and able to speak to first-responders before being taken to a Cape Cod hospital.
Davis said the man was less than 25 yards from shore when he was injured.
If it was a shark, "I've never seen that, not that close to shore," Davis said.
The beach remained open, but Davis said National Seashore personnel would post a sign warning beachgoers to beware of sharks.
He also said there were seals in the area at the time of the incident, and the seals may have been a lure to a shark.
Greg Skomal, a marine biologist for the Massachusetts Division of Marine Fisheries, told CNN recently that more great white sharks are being seen off the coast of Cape Cod each year.
"As we've allowed seal populations to rebound over the course of the last four decades, I believe that they've now hit threshold levels that are drawing these sharks close to shore," Skomal said.