The United Kingdom has seen its first confirmed domestic death from coronavirus as the number of known cases doubled in two days to 116.

Axar.az reports citing foreign media that the first victim was British woman is believed to have been 75 and had been “in and out of hospital” with an underlying health condition. She was diagnosed with coronavirus when NHS staff were conducting routine tests of intensive care patients with respiratory problems for pneumonia. She died at the Royal Berkshire Hospital in Reading, Berkshire, on Thursday.

It is unclear as to how she contracted the China-origin virus, as The Times reports the frail woman had not been traveling nor been in contact with anyone known to have been infected, suggesting that coronavirus is being passed on undetected.

“Our sympathies are very much with the victim and their family,” Prime Minister Boris Johnson told reporters.

A second fatality was reported on Friday afternoon, but there has been no official confirmation. No further details of the victim were released at the time of reporting.