South Korea has reported its biggest jump in coronavirus infections in seven weeks on Wednesday, driven by a fresh cluster at an e-commerce warehouse on Seoul’s outskirts, as millions more pupils went back to school.

The country has been held up as a global model in how to curb the virus and has rushed to contain new infections as life returns to normal.

According to officials, there are 40 fresh COVID-19 cases on Wednesday — taking its total to 11,265 — with most new infections from the densely populated Seoul metropolitan area.

It was the largest increase since 53 infections were announced on April 8.

Vice Health Minister Kim Gang-lip said, “It is suspected that the basic regulations were not enforced at the warehouse”.

“If quarantine rules are not implemented at workplaces, it could lead to a dreadful result of a mass infection”, Kim further added.

More than two million students returned to classes on Wednesday, as part of the phased reopening of schools.

Some high schools were forced to turn back pupils shortly after resuming classes last week over concerns of new virus cases in their neighbourhood.

Earlier in the month, President Moon Jae-in urged the public to remain vigilant as the capital has ordered the closure of all clubs and bars after a burst of new cases sparked fears of a second coronavirus wave.

At least 1,138 infections have been linked to international arrivals, but such cases have declined after the country strengthened border controls in April, enforcing two-week quarantines on all passengers coming from abroad.

President Moon the new cluster had “raised awareness that even during the stabilisation phase, similar situations can arise again anytime”.

According to the Health Minister Park Neung-hoo, school officials to double check their preventive measures.

The country endured one of the worst early outbreaks of the disease outside mainland China, and while it never imposed a compulsory lockdown, strict social distancing had been widely observed since March.

(With inputs from agency)