Coronavirus has infected 106,000 people in the last 24 hours, the largest number of cases since its outbreak, the WHO said on Wednesday.
Revealing the alarming numbers at his daily briefing, WHO Director General Tedros Adhanom Ghebreyesus said that two-thirds of those cases came from just four countries, the BBC reported.
The global tally of cases is nearing five million, with more than 324,000 deaths, according to figures collected by Johns Hopkins University's Coronavirus Resource Centre.
The US currently has the most cases, with 1.5 million, followed by Russia, Brazil and the UK.
Meanwhile, a senior official of the World Health Organization (WHO) has warned against using hydroxychloroquine or chloroquine, the drugs for malaria and other diseases, in the treatment of Covid-19, saying these drugs should be reserved for use "within clinical trials".
"Warnings have been issued by many authorities regarding the potential side effects of the drug and many countries have limited its use to that of clinical trials or during clinical trials or under the supervision of clinicians in a hospital setting that's specifically for Covid-19, because of a number of potential side effects that have occurred and could occur," Dr Michael Ryan, executive director of the WHO Health Emergencies Programme, said.