Unidentified gunmen on Saturday attacked a terminal on the gas pipeline to Israel for the fifth time since February, a security official said.
Gunmen on motorbikes and cars lobbed grenades and tried to storm the terminal at Al-Shulaq in north Sinai but were confronted by armed forces, leading to clashes.
Witnesses said the gunmen managed to flee.
"Unidentified gunmen attacked the natural gas terminal on the pipeline to Israel. There was no gas in the pipeline since it was blown up on July 11," the security official said.
It was the fifth attack on the gas pipeline since February, a time of political upheaval when an uprising toppled former president Hosni Mubarak and saw power handed over to a military council.
Earlier this month, saboteurs bombed the pipeline cutting supplies to Israel and Jordan.
Egypt supplies about 40 percent of Israel's natural gas which is used to produce electricity.
Jordan, which buys 95 percent of its energy needs, imports about 240 million cubic feet (6.8 million cubic metres) of Egyptian gas a day, or 80 percent of its electricity requirements.
The attack comes a day after clashes in the nearby city of El-Arish that left five people dead.
Armed forces arrested 12 men, including three Palestinians, suspected of involvement in an attack on an El-Arish police station, said north Sinai security chief Saleh al-Masri.
Three civilians, an army officer and a police officer were killed in the clashes, and 19 people wounded.
Earlier on Friday, around 150 men in trucks and on motorbikes rampaged through El-Arish, firing assault rifles in the air, driving terrified residents into their homes.
They rode through the deserted streets of the city waving black flags which read "There is no God but Allah", before attempting to storm the police station.
Earlier, the masked men used a bulldozer to damage a statue of the late president Anwar Sadat, who was assassinated by Islamist militants in 1981.
The violence came after a peaceful demonstration at noon in one of the city's squares, part of countrywide protests on Friday by Islamists who want any future constitution to assert that Egypt is a Muslim state.