A car had parked near the pipeline in the Bir al-Abd area, 80 kilometers (about 50 miles) from the north Sinai town of El-Arish, shortly before the blast occurred, AFP quoted Egyptian officials as saying on Monday.
Emergency services were dispatched to the area to try to bring the fire under control, a security official said.
According to a security source, unknown men with machine guns in a small truck forced guards at the station to leave, then planted explosive charges.
The natural gas company that runs the pipeline closed it down after the explosion, the source added.
The Monday attack was the third such incident since February when the three-decade authoritarian rule of former Egyptian President Hosni Mubarak came to an end after 18 days of protests.
No groups or individuals have claimed responsibility of the attack yet.
It is only 24 days since Egypt resumed pumping natural gas to Israel after supplies were halted for more than a month due to an act of sabotage.
Egypt said in April it would review its gas contracts with other states including Israel and Jordan. The exports have long been a controversial issue in Egypt, as Mubarak’s regime was accused of selling gas too cheaply to Israel.
Egypt provides for up to 45 percent of Israel’s gas imports according to a 20-year contract signed in 2005.
Following an April attack, Egyptian authorities stepped up security measures along the 192-kilometer (119-mile) pipeline.