An attacker fired birdshot at an Egyptian security post outside a hotel near the Giza Pyramids on Thursday morning, the Interior Ministry said.
The ministry said no one was hurt in the incident at the Three Pyramids Hotel, but the attack damaged the hotel's facade and also a bus parked in front of the building.
According to a ministry statement, the shooter was part of a group of about 15 people who threw flares at the hotel's security post. A suspect was arrested and police were still searching for the rest of the group, the statement said. It did not identify the arrested suspect.
The motive for the attack was unclear and no one immediately claimed responsibility for it. However, a witness at the scene indicated the attack was more organized than the ministry described and that deadly weapons were used.
"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," said Jaber Jabarin, an Arab Israeli citizen who was staying at the hotel and witnessed the attack.
After throwing Molotov cocktails, Jabarin said the attackers "started firing at the hotel with live bullets." He described heavy, continuous gunfire.
His account and the ministry's statement could not be immediately reconciled.
In Jerusalem, Alon Lavi, a spokesman for Israel's Foreign Ministry, said the bus that was hit was in use by a group of visiting Arab Israelis but that no one was inside the bus at the time of the incident and that no Israelis were hurt. He said Israel was briefed on the incident by the Egyptian Foreign Ministry.
The attack came as Egyptian's Coptic Orthodox Christians were celebrating the Orthodox Christmas in predominantly Muslim Egypt. Most Orthodox Christians follow the older, Julian calendar and celebrate Christmas on Jan. 7. In Egypt, thousands of policemen were deployed across Cairo and other cities to protect churches and Christian celebrations.
The Egyptian government has for years been battling an insurgency by Islamic militants in the northern part of the Sinai Peninsula. Attacks on security forces there have significantly escalated after the military overthrew the country's first freely elected President Mohamed Morsi in 2013. There have also been attacks in the mainland.