Shark patrols are ramping up off Long Island beaches after five people were bitten in two days by marine animals that are likely sharks, authorities say.

Officials in Long Island's eastern Suffolk County, where three of the attacks occurred, have increased beach patrols and are using drones to scour the water for potential threats, the Suffolk County Police Department said Tuesday.

The spree of bites has left New York beachgoers on high alert and recalls a similar spate of non-fatal shark attacks last summer that triggered several beach closures.

A school of approximately 50 sharks was spotted by a drone near Robert Moses Beach Tuesday morning -- the same day a 15-year-old girl was bitten while swimming at that beach, according to George Gorman, the Long Island Regional Director for New York State Parks, Recreation and Historic Preservation.

Though no sharks were seen by the girl or anyone nearby at the time of the incident, the bite was most likely from a shark, Gorman said.

Also Tuesday, a 15-year-old boy was bitten on his foot by a shark while surfing off Fire Island's Kismet Beach, Suffolk police said.

Both teens had non-life-threatening injuries, authorities said.

Three more people were bitten on Tuesday, including a 47-year-old man swimming in chest-deep water off of Long Island's Quogue Village Beach, local police said. The bite left him with lacerations on his knee and was from a "larger marine animal" preliminarily believed to be a shark, the Quogue Village Police Department said.

The two others who were bitten -- a 49-year-old man at Pines Beach and a woman west of Cherry Grove -- both sustained non-life-threatening injuries, police said.

The police department has encouraged people to continue to enjoy the beach but urged swimmers to be vigilant and look out for sharks or pods of fish that may attract predators.

New York's Office of Parks, Recreation and Historic Preservation has also increased up its water surveillance over the past year, Gorman said.

"We have great surveillance, drones and lifeguards scanning and checking the beaches," Gorman said.

Gavin Naylor, the director of the Florida Program for Shark Research, told CNN "This Morning" that there are precautions swimmers can take to enjoy the beach safely and avoid attacks.

"People should always swim in groups. They shouldn't swim too far from the shore, and they should particularly avoid bait fish," Naylor said.

Though they may be making headlines again this summer, the risk of being attacked by sharks remains low.

The Florida Museum of Natural History documented 57 confirmed, unprovoked attacks worldwide last year. Of those, 41 were in the United States, with eight non-fatal incidents in New York.