The southern Africa nation, which has recorded more than 47,000 cases since the outbreak last year, has seen its 7-day average infection rate increasing five times to 727 compared to two weeks ago.
Mnangagwa said businesses would now open between 8 a.m. and 3 p.m. while a curfew would start from 6:30 p.m. to 6 a.m. Companies would be required to only have 40% of their workforce, he said.
The measures would be in effect for two weeks, after which they would be reviewed.
Under the level four lockdown measures, travellers to or from Zimbabwe who use fake certificates for a negative coronavirus test face jail time, Mnangagwa said.
Zimbabwe has vaccinated 764,248 people and last week the government said it was expecting 2.5 million more vaccines from China to help boost its vaccination drive.