Britain has recorded two new cases of avian flu in workers who had contact with infected birds.
The two people affected worked at different premises said the UK Health Security Agency (UKHSA) and were detected after a test for people with no symptoms but who had been in contact with infected birds.
In May, the UKHSA recorded two infections detected through the same programme that identified these latest cases.
Human cases of bird flu come in two types said the agency; either a true infection or alternatively a nose and throat contamination caused by breathing in affected materials.
"The first new detection is difficult to interpret due to lack of information on sample timing and may be consistent with infection or contamination of the respiratory tract," the UKHSA said.
"The second new detection is likely to represent contamination. Precautionary contact tracing was undertaken."
There was no evidence of human-to-human contamination, said the agency, with risk to the widespread general population still rated as very low.