New variants first detected in countries like Brazil, South Africa, Nigeria and Britain have cropped up in Canada recently.
Maharashtra's chief minister says the state's health system could soon become "inadequate".
Health officials in Virginia have reported the first cases in the state of a highly contagious coronavirus variant that first emerged in California last summer.
Order comes less than a week after plans to reopen businesses reversed while vaccine teams will target high-risk workers
Two cases of the COVID-19 P.1 variant have been detected in Colorado, the Centers for Disease Control announced Tuesday.
EXCLUSIVE: Cases have continued to fall in all adult age groups since schools reopened in England on March 8, with the return to classrooms yet to trigger an increase in the infection rate.
The latest data from the CDC shows Massachusetts has 441 confirmed cases of the B.1.1.7 variant, which was first discovered in the United Kingdom.
New cases worldwide increased by 8% over the last week, the fifth week in a row that the WHO has seen an increase in transmission, one official said.
The Department of Health has announced the detection of more cases from four COVID-19 variants in the country from results of genome sequencing of a combined 1,361 samples.
The double-mutant strain contains two key mutations, E484Q and L452R, that have been found separately in other variants but not together in a single strain.