The navy attacked Palestinian fishing boats in the northern besieged on Thursday evening.
The were sailing off the shore of the As-Sudaniya and Al-Waha areas when they were fired at with guns, tear gas and water hoses, according to the Palestinian Authority's Wafa news agency.
The fishermen were forced to flee for their safety, Wafa said.
Israel often targets Palestinian fishermen in the besieged Gaza Strip, using live fire and water cannons, torn fishing nets, and damaged boat engines to prevent fishermen from carrying out their work.
Before Israel imposed a blockade on the Gaza Strip more than 15 years ago, fishermen could work in the open sea and each earned at least $50 a day.
The blockade means they currently struggle to earn $10 a day.
Fifteen years of siege
In 2007, Israel imposed a land, sea, and air on the Gaza Strip, effectively turning the coastal enclave into an open-air prison. The transport of basic necessities such as food, fuel and medicines into Gaza is severely restricted.
Critics say the blockade, along with a periodic bombardment of Gaza, amounts to of the coastal enclave's 2 million residents.
In 2014, the UN - along with four other human rights organisations - said that the Gaza Strip could end up becoming 'uninhabitable' because of Israeli policies. The decade-long siege has plunged hundreds of thousands of Palestinians into poverty.
Nearly 70 percent of Gaza's population is food insecure and around 80 percent of Palestinians in the besieged enclave are reliant on international aid, according to the United Nations.
Of Gaza's 1.8 million population, 1.4 million are refugees whose ancestors were forced out of their homes in what is now Israel during the 1948 Arab-Israeli war.