Tehran, Sept 21, 2019 (AFP)

Iran denied on Saturday its oil infrastructure had been successfully attacked by a cyber operation, after reports of disruptions to the sector online.

"Contrary to Western media claims, investigations done today show no successful cyber attack was made on the country's oil installations and other crucial infrastructure," the government's cyber security office said.

The statement did not specify which reports it was addressing.

NetBlocks, an organisation that tracks internet outages, tweeted early Saturday that "network data show intermittent disruptions to internet connectivity in #Iran."

But it said the cause was unclear and impact limited, affecting "online industrial and government platforms" and specific providers.

"Data are consistent with a cyber attack or unplanned technical incident on affected networks as opposed to a purposeful withdrawal or shutdown incident," it added.

Iran's Telecommunications Minister Mohammad Javad Azari Jahromi has acknowledged in the past that Tehran has "been facing cyber terrorism -- such as Stuxnet."

The Stuxnet virus, discovered in 2010, is believed to have been engineered by Israel and the US to damage nuclear facilities in Iran.

Iran at the time accused the US and Israel of using the virus to target its centrifuges used for uranium enrichment.