An explosion hit a gas pipeline running from Egypt to Israel on Sunday, witnesses and state television reported.
The pipeline, which also supplies gas to Jordan, has come under attack at least 12 times since Egyptian president Hosni Mubarak was toppled in 2011.
The latest blast took place in the Massaeed area west of the Mediterranean coastal town of al-Arish. Gas pumping was stopped after the explosion.
Residents in al-Arish told Reuters they could see flames from their town. Security forces and fire trucks raced to the scene, witnesses said.
Security in Sinai loosened after Mubarak's fall as the police presence thinned out across Egypt.
Egypt's 20-year gas deal with Israel, signed in the Mubarak era, is unpopular with some Egyptians, with critics accusing Israel of not paying enough for the gas.
Previous explosions have sometimes led to weeks-long shutdowns along the pipeline, run by Egypt's gas transport company Gasco, a subsidiary of the national gas company EGAS.
Egypt said in November it would tighten security measures along the pipeline by installing alarm devices and recruiting security patrols from Bedouin tribesmen in the area.
Sinai has long been a restive area, where Bedouins complain of government neglect. It hosts several Red Sea resorts with five-star hotels, but Bedouins say they do not see the benefits.
Egypt doubled the gas price for Jordan in October. Jordan said on Monday it would raise electricity prices as of February to cover the rising burden of imported fuel costs after loss of regular Egyptian gas supplies.