On Wednesday, cases more than doubled from 56 to 132, stunning officials who had only announced a previous daily high of five since the virus first landed in the country on March 20.
The country has also recorded four deaths and 28 recoveries.
“Seventeen cases tested positive for Covid-19 today. These are all returnees from Mozambique registering nine, South Africa with seven and the United Kingdom with one,” the ministry of health said in an update.
It said all 17 individuals were being held in quarantine centres in Beitbridge, Masvingo and Harare.
Zimbabwe has conducted 16,440 polymerase chain reaction tests to date, which health experts say is too low.
The virus has killed over 360,000 people from 5.8 million infections worldwide. Some 2.4 million people have made recoveries.
Zimbabwean officials say 118 people have escaped from quarantine centres where returnees are detained for a mandatory 21-days.
Zimbabwe’s information minister, Monica Mutsvangwa, on Wednesday told reporters that the government is increasing security at the schools, colleges and hotels used as quarantine centres
Government spokesman Nick Mangwana suggested that security officers guarding centres with high walls and razor wire might be receiving bribes to allow people to leave early.
Zimbabwe’s government is also worried about people crossing porous borders and failing to report at quarantine centres. The information ministry has begun sharing a hotline number and asking people to stop harbouring “border jumpers” and those who “abscond” from quarantine.