Saboteurs blew up a pipeline carrying gas from Egypt to Israel and Jordan on Monday, forcing a shutdown in the flow of gas, Egyptian security sources said.
The explosion took place in the early morning at a station along the pipeline in the northern Sinai Peninsula at Bir Abd, 60 km east of the Suez Canal, the sources said.
It was the third attack since early February on the pipeline, which supplies natural gas to Israel and Jordan, local cement plants and a power station.
A security source said men with machine guns in a small truck forced guards at the station to leave, and then planted explosive charges.
"We do not have sufficient information until now, but in principle the explosion happened in the same way that the two previous explosions happened," another security source told Reuters.
The natural gas company that runs the pipeline closed it down after the explosion, the source said.
Witnesses said the sound of the explosion boomed out across the desert, frightening nearby residents, and tongues of fire could be seen above the station.
Previous explosions on April 27 and Feb. 5 closed the pipeline for weeks, and another attempt to shut down the line failed in March.
In April, masked gunmen blew up the al-Sabil natural gas terminal near Egypt's border with Israel, sending flames shooting into the air in the early hours of the morning and forcing the shutdown of the country's gas export pipeline to Israel and Jordan.
The month before, another attack hit the same terminal, which is just 50 kilometers (30 miles) from the border with Israel. Gunmen planted explosives at the terminal, however they failed to detonate.
In February, Bedouin tribesmen in the area blew up a section of the pipeline, stopping exports to Israel and Jordan for a month. They also attempted to sabotage the pipeline in July 2010.
The pipeline is run by Gasco, Egypt's gas transport company which is a subsidiary of the national gas company EGAS.
Egypt's gas deal with Israel has been the subject of much controversy in Egypt and has sparked protests for years.
More recently, deposed President Hosni Mubarak and officials from his regime have been placed on trial over allegations of corruption involving gas sales to Israel.
The officials are accused of selling gas to Israel and countries in Europe for below-market prices, and thus cheating Egypt out of billions in lost income.