The graves were discovered near the town of Beit Lahia, at the site of construction works for a residential area.
Naji Sarhan, an official with Gaza's Ministry of Public Works, confirmed the find and reported "evidence" of other graves at the site.
Construction work has been halted and experts from Gaza's Ministry of Antiquities and Tourism have begun cataloging tombstones and artifacts, officials said.
An expert, who requested anonymity, said the graves were believed to be part of a cemetery linked to the nearby Roman site of Balakhiya.
The discovery is the latest in Gaza, where tourist visits to archaeological sites have been restricted since the blockade imposed by Israel following the Hamas takeover in 2007.
Roman-era tombs discovered at a construction site in Beit Lahia, in the northern Gaza Strip, on February 20, 2022 MOHAMMED ABED AFP
Israel and Egypt, countries bordering the Gaza Strip where some 2.3 million Palestinians live, severely restrict entry and exit to and from Palestinian territory.
Last month, a 5th-century Byzantine church was reopened by Hamas after years of restoration work, supported by foreign donors.
© 2022 AFP