The Food Standards Agency warned consumers across the United Kingdom on Sunday to avoid eating runny or undercooked eggs as a salmonella outbreak linked to a recalled batch continued to spread. The agency advised the public to check batch codes and dispose of affected products.

The warning followed escalation of a large egg recall, which the US Food and Drug Administration separately upgraded to its highest-risk category earlier in the week. In the UK, the FSA and the UK Health Security Agency have been tracking a rising number of confirmed Salmonella enteritidis cases tied to eggs sold at major retailers.

Young children, pregnant women, older adults and people with weakened immune systems face the greatest risk of serious illness. The UKHSA said symptoms typically include diarrhoea, stomach cramps, fever and vomiting, and urged anyone with severe or prolonged symptoms to contact NHS 111.

The FSA advised consumers to cook eggs until both the white and yolk are solid and to avoid dishes containing raw egg, such as homemade mayonnaise and mousse. Retailers were instructed to remove affected batches from shelves and display point-of-sale recall notices.

A Food Standards Agency spokesperson said the investigation was ongoing and that further batch withdrawals could follow as testing continued. The agency asked anyone who had bought recalled eggs to return them for a full refund.