An Egyptian pipeline sending gas to Israel and Jordan was hit by a fresh explosion early Thursday, Egypt's security services said.
The blast occurred 40 kilometres (25 miles) west of the town of al-Arish in the north of the Sinai peninsula, a security source said.
The pipeline, which carries gas through the Sinai and on to Jordan and Israel, had already been attacked six times since former president Hosni Mubarak was toppled in February.
Witnesses said they had seen armed men at the scene, the source said. He did not know if there had been any victims.
Previous attacks have disrupted gas deliveries to both countries several times, but it was not immediately clear what impact the latest incident would have.
The most recent attack was on September 27 and left one person injured.
Army experts have also located and defused a number of other devices targeting the pipeline.
Israel generates 40% of its electricity using natural gas, and Egypt provides 43% of its supplies of the material.