State-owned Saudi Aramco has been forced to shut down its entire computer network after an attack by a computer virus.

Production was not affected, according to an Aramco statement, Reuters news agency reports.

The virus did not penetrate the key components of Saudi Aramco’s network. The company isolated its systems and cut off external access as a precaution, says the statement.

Saudi Aramco is the largest oil exporter in the world and produces about 10 million barrels a day (b/d).

Iran has been subject to a series of virus attacks on its computer networks associated with its nuclear plants over the last two years.