Saudi Arabia is stopping pilgrims from entering the country to travel to some of the holiest sites in Islam over coronavirus fears.
It comes as for the first time, new cases of Covid-19 outside of China are increasing faster than those inside the country, with South Korea, Iran and Italy particularly hard-hit.
Authorities in Saudi Arabia have also suspended entry to the kingdom to those with tourist visas from nations affected by the new virus.
Currently, there are no reported cases of Covid-19 - the strain of coronavirus spreading across the world - in Saudi Arabia, but in the past week, the Middle East has confirmed 220 cases, the majority of which are in Iran where the most deaths outside of China have occurred.
The extraordinary decision by Saudi Arabia stops foreigners from reaching the holy city of Mecca - the birthplace of the Prophet Muhammad - and the Kaaba, the cube-shaped structure the world's 1.8 billion Muslims pray toward five times a day.
The decision also affected travel to the Prophet Muhammad's mosque and burial site in Medina.
Saudi Arabia welcomes millions of Muslim visitors throughout the year - with a peak for the Hajj pilgrimage, due to begin this year in July.
Unlike the Hajj - which is required of all able Muslims at least once in their life - the Umrah can take place at any time of the year - but those journeys have now been stopped for foreigners.
The ministry of foreign affairs said the suspensions were temporary - but did not say when they would end.
The decision by Saudi Arabia demonstrates the country's fears about Covid-19 spreading to the kingdom whose oil-rich monarchy stakes its legitimacy on protecting Islam's holy sites.
“Saudi Arabia renews its support for all international measures to limit the spread of this virus, and urges its citizens to exercise caution before traveling to countries experiencing coronavirus outbreaks,” the Saudi Foreign Ministry said in a statement announcing the decision.
“We ask God Almighty to spare all humanity from all harm.”
It is thought 400,000 tourist visas for Saudi Arabia have been issued since October.
More than 82,000 cases of Covid-19 have been confirmed around the world, with the majority of them in China where the virus originated.
More than 2,700 people in China have died from the disease, although in recent days the number of deaths appeared to be slowing.
However, in the rest of the world, the number of cases are accelerating and for the first time more new cases have been confirmed outside China than inside the country.
South Korea has the highest number of cases outside of China, with almost 1,600 confirmed on Thursday and 13 deaths.
In Europe, Italy has the most cases, with 400 people diagnosed and 12 deaths.
World Health Organisation director-general Tedros Adhanom Ghebreyesus has described the "sudden increases of cases in Italy, the Islamic Republic of Iran and the Republic of Korea" as "deeply concerning".
In the UK, a number of schools have closed and pupils and staff have been sent home after half term ski trips to northern Italy - the region of the country worst-hit by the disease.
Pupils at Prince George and Princess Charlotte's school are among those to have self-isolated after returning from northern Italy.
Four pupils from St Thomas's Battersea School in south-west London were told to stay home amid concerns they may have the Covid-19 virus.
The number of Covid-19 cases remains at 13 in the UK.
The Foreign Office has said there are no plans to evacuate those staying at the H10 Costa Adeje Palace, but it had arranged for written messages to be put under the doors of the rooms of British guests asking them to get in contact.
In the US 60 cases have now been confirmed, although most are amongst people who were evacuated from outbreak zones.
On Wednesday, President Donald Trump said America is “very, very ready” to handle the coronavirus outbreak and put Vice President Mike Pence in charge of the domestic response to the virus.
“This will end,” Mr Trump said of the outbreak as he insisted the outbreak would not necessarily become a pandemic - an illness prevalent across the world.
“You don’t want to see panic because there’s no reason to be panicked.”