Tokyo Governor Yuriko Koike has said that she would ask the central government to impose emergency measures in the capital region to stem a surge of Covid-19 infections, Reuters reports.

Koike made the comments after a meeting with medical experts who warned of an explosive surge in cases that could exceed the third and most deadly wave of the pandemic so far. Experts also warned of a rise in more infectious mutant strains of the virus.

“This is a very worrisome situation,” Koike said. “And we need to be more vigilant of the increase in the number of people infected with the mutant strains.”