South Korea’s health minister on Monday said the Seoul metropolitan area is now a “Covid-19 war zone”, as the country reported another 615 new infections and the virus appeared to be spreading faster.

The president, meanwhile, issued a call to expand testing and contact tracing. The country has recorded more than 5,300 new infections in the past 10 days and Monday was the 30th day in a row of triple-digit daily jumps.

Most cases have come from the densely populated Seoul metropolitan area, where half of South Korea’s 51 million people live. With people increasingly venturing out in public and spending longer hours indoors amid cold temperatures, health workers have struggled to stem transmissions tied to restaurants, saunas, schools, hospitals and long-term care facilities.

“The capital area is now a Covid-19 war zone,” Health Minister Park Neung-hoo said in a virus meeting, asking for vigilance.

He said the country may have to increase social distancing to prevent the resurgence in the capital area from “exploding into a major outbreak nationwide and collapsing the health care system”.

Na Seong-woong, a senior official from the Korea Disease Control and Prevention Agency, told reporters the country could be reporting around 900 new infections a day next week if it fails to slow the virus quickly.

While South Korea managed to contain a major outbreak in its southeastern region in spring by channelling nationwide health resources and personnel, it is less clear where the reinforcements will come if the virus wreaks havoc in the Seoul area.

While President Moon Jae-in’s government had been eager to tout the country’s previous gains against the virus, there is criticism that it gambled on its own success by moving quickly to ease social distancing restrictions to the lowest level in October even as the virus was still spreading.

Officials have moved to restore some distancing restrictions in the Seoul area in recent weeks, shutting down nightclubs, karaoke rooms and gyms, reducing in-person school classes and allowing restaurants to provide only delivery and takeaway after 9pm.

City officials in Seoul have also reduced public transport after 9pm to discourage unnecessary gatherings, although some say the move might backfire by making buses and undergrounds more packed.

Some health experts have endorsed stronger restrictions, such as banning all gatherings of more than 10 people, shutting down schools and churches and requiring companies to have more employees work from home.

Moon expressed concern on Monday that health workers are increasingly struggling to track transmission routes amid the rising infections, urging officials to deploy the “maximum available manpower” of civil servants, police and military personnel to assist with contact tracing efforts in the capital area, his spokesman Chung Man-ho said.

Chung said Moon also instructed officials to keep more testing stations open during night hours or holidays and install more “drive-through” set-ups that allow workers to collect samples from drivers through car windows.

He also asked “any citizen who has the slightest suspicion of being infected to visit a screening centre to get tested”, Chung said.

During a separate briefing, Na said health officials are planning to adopt new testing techniques, including rapid antigen tests and salvia-based tests, so that they could screen potential virus carriers more quickly.

The country mainly relies on a diagnostic testing method called PCR, which is more accurate but also more complicated.

The country’s has reported 38,161 infections since the pandemic began and 549 deaths.