Asahi has partially restarted production at all six of its breweries in Japan after it was forced to close them due to a cyber-attack.

Several major shops in Japan including 7-Eleven and FamilyMart had warned last week that they were running low on stocks of the beer after the hack affected Asahi Group’s ordering and delivery systems in the country.

Asahi is the biggest brewer in Japan, but it also makes soft drinks and food products, as well as supplying own-brand goods to other retailers.

The partially restarted breweries produce best-seller Asahi Super Dry, but the firm is also restarting plants that produce food and soft drinks.

The cyber-attack is the latest to have affected operations at major firms, with carmaker Jaguar Land Rover still struggling to recover from an attack that shut down production.

Asahi Group also owns Fullers in the UK and global brands including Peroni, Pilsner Urquell and Grolsch. However, only Asahi’s operations in Japan – which account for about half its sales – have been affected by the attack.

Asahi said the re-opened beer plants in Japan were “not yet fully operational”, and that two of its soft drinks factories that have partially re-opened were also not running at full capacity.

It added there were a further five soft drinks factories that “will resume gradually in accordance with shipments.”

All seven of its food plants have resumed operations, though they are also not yet fully operational.

Asahi said the production systems at the factories themselves had not been affected by the cyber-attack, but it had been forced to halt production because it could not process orders and shipments.

On Friday, Asahi said said it was “unable to provide a clear timeline for recovery” but that it was working with external cyber-security experts to restore its systems as soon as possible.