Massive group transmission cases have been avoided thanks to nationwide efforts to practice social distancing and stamp out the novel coronavirus, the government said Saturday.

The government announced that it will lengthen the period of its social distancing guidance for two weeks until April 19 to help curb the spread of the virus that has killed at least 177 here.

“As a result of the social distancing campaign, it clearly proved its effectiveness in preventing the spread of infections without extreme closures of businesses or movement restriction measures,” the Central Disaster and Safety Countermeasure Headquarters said.

Through the drive, the country aims to cut down the number of daily new infections to below 50. It confirmed 94 new infection cases Friday, with the figure fluctuating at around 100 since late March.

In a detailed view, virus infections due to cluster transmissions have significantly dropped -- by 70 percent when comparing the number of cases in the 11 days before and 11 days after the intensive campaign began on March 22.

Cases with an unknown source of infection have also dwindled from an average of 57 infections a day in the first week of March to five last week, health authorities said.

“After strengthening the social distancing requirements, it became clearer to trace the source of infection of new confirmed cases and it helped keep infections to a manageable level,” Health Minister Park Neung-hoo said during a press conference.

The guideline forces major public facilities, including schools and gyms, to shut down, while advising people to keep a distance of at least 2 meters from each other and avoid nonessential gatherings.

Some modest clusters of the virus across the country have been contained enough to avoid widespread further transmission, such as at Manmin Central Church, located in southwestern Seoul’s Guro-gu.

So far, 45 cases have been reported among followers of the church. But the number could have been much higher if it had not switched its regular services -- where some 4,000 to 5,000 members gather -- into online services.

Temporary shutdowns of child care centers and nursing homes helped in blocking people who were infected in other clusters from spreading the virus, according to Park.

By Park Han-na (hnpark@heraldcorp.com)