Saboteurs on Monday blew up a pipeline that supplies gas to Israel, the 12th such attack in a year, security officials said.
Masked gunmen planted explosives under the pipeline in the Al-Massaeed area, close to the town of El-Arish in the north of the Sinai peninsula, they said.
Witnesses said they heard a very loud explosion, before a large fire broke out.
Sources say the attack on the pipeline came the day after an Islamist leader from the area died in his prison cell in Cairo. Interior ministry officials said he died from natural causes.
Emergency services were rushed to the scene to try to control the blaze, the official said, adding that there were no immediate reports of casualties.
The pipeline, which carries gas through the Sinai and on to Jordan and Israel, has already been attacked 11 times over the past year, the first during the mass uprisings that drove President Hosni Mubarak from power in February 2011.
Gas deliveries to Israel, agreed under Mubarak, have come under heavy criticism in Egypt.
Israel generates 40 percent of its electricity using natural gas, and Egypt provides 43% of its gas supplies.
Egyptian gas also covers 80 percent of Jordan's electricity production demand -- 6.8 million cubic metres a day.
Egypt's Sinai region is particularly security sensitive due to tensions with the Bedouin community living there, which is heavily armed.
Many goods are smuggled to the Palestinian enclave of Gaza through the Sinai, which the Israelis also charge is a rear base for militant attacks against its territory.