Egyptian police say there were no injuries in the attack, which happened as around 40 holidaymakers prepared to board a bus at a four star hotel. Security sources say the tourists were Israeli Arabs.
Thursday's shooting took place at the Three Pyramids Hotel, in southwest Cairo on a road leading to the Giza pyramids.
Reuters cited security sources say that gunmen opened fire on the Israeli tourists as they were boarding a bus, while other news agencies reported that the police, who were guarding the visitors, were targeted.
A group of 40 Arab Israelis had been due to board the bus, but were still inside the hotel when the shooting broke out.
Egypt's interior ministry said in a statement that a group of around a dozen young assailants threw firecrackers and fired buckshot in the direction of the bus, adding that police returned fire. No one was injured in the attack, it said.
"One of the loiterers fired a home-made pellet gun in the direction of the security in front of the hotel, causing some damage to the glass facade of the hotel as well as the window of a tourist bus," said the statement.
Hotel guest and witness Jaber Jabarin told the Associated Press:"The first thing they fired was flares, and then they started firing at the bus. Later they started firing birdshot at the hotel and tried to throw Molotov cocktails at the bus." He also described heavy, continuous gunfire.
One gunman was arrested at the scene, while another was arrested later in a different part of Cairo.
There has been no claim of responsibility for the attack and police said no motive was immediately apparent.
The shooting took place amid tight security during Orthodox Christmas, which is celebrated by Egypt's minority Coptic Christians.
Last year, Egypt vowed to step up security at major tourist attractions after Islamist militants carried out several attacks, causing a further slump in its struggling tourism sector.
In June last year, a suicide bomber blew himself at an ancient temple in the southern city of Luxor, wounding three Egyptians.
mm/mg (AFP, AP, Reuters)