Nearly seven million people in the US state of Texas have been told to boil tap water before consuming it after a deadly winter storm caused power blackouts at treatment facilities.
The huge storm sweeping across the southern US has killed at least 24 people and left millions without power.
Texas has seen widespread outages.
Freezing temperatures have also caused water pipes to burst, despite attempts by some homeowners to insulate them from the cold using blankets.
The state’s energy grid has been overwhelmed by a surge in demand as people try to keep warm in some of the coldest temperatures there in more than 30 years – hitting 0F (-18C) earlier this week.
Over 13 million people – close to half of the state’s population – have faced some disruption of water services.
US President Joe Biden earlier approved a state of emergency for Texas, which has been blanketed by snow and ice since the storm swept in at the weekend.
What’s happening in Texas?
A so-called “boil water notice” has been issued for the city of Houston and surrounding areas, with the US Centers for Disease Control and Prevention (CDC) advising that all water planned for consumption – even if filtered – must be boiled as it may be contaminated.
Only boiled or bottled water should be used, including for brushing teeth, the CDC said.
The mayor of Houston, Sylvester Turner, urged those without power – and unable to boil tap water – to try to access bottled water wherever possible.
“Power will not be restored fully, I would say, probably for another couple of days,” he told reporters at a press conference.
Houston police and disaster response teams will be delivering bottled water to those with disabilities who do not have access to transportation, the mayor said on Thursday.
Mr Turner also urged people who had been leaving taps running to prevent pipes from freezing not to do so, in an effort to help conserve supplies.
