Another new strain of Covid-19 has been detected in the UK, just days after a second new variant caused travel chaos across Europe.
Two people in the UK have tested positive for the new Covid-19 mutation - both contacts of cases who've travelled from South Africa in recent weeks.
At a press conference on Wednesday UK Health Secretary Matt Hancock said the new variant is highly concerning, because it is yet more transmissable.
The South African version appears to have mutated further than the first variant discovered in the UK this week.
Hancock says the UK is placing immediate travel restrictions on travel from South Africa.
Anyone in the UK who has been in South Africa in the past fortnight and their close contacts must quarantine immediately.
Multiple areas of the United Kingdom will be escalated to tier four lockdown measures on Boxing Day.
UK correspondent Vincent McAviney speaks to Māni Dunlop.