LONDON (Reuters) – Britain’s Department of Health said its coronavirus tracing system contacted 31,794 people between 28 May and 3 June and of those it was able to reach 26,985, or 85%, and advise them to self-isolate.

The government’s test and trace system is seen as key to helping to ease lockdown measures.

The 31,794 people were contacts of a group of 5,407 people who had tested positive for coronavirus and provided details of those they had met to the system, said the Department of Health on Thursday.

However only two-thirds of the 8,117 people who tested positive for the virus during the period provided details of recent contacts to the system, with the remaining number not able to be reached.