SEOUL (REUTERS) - South Korea reported 63 new coronavirus cases as of Thursday (July 2), most from domestic infections outside Seoul, triggering the return of tighter social distancing curbs in one city as the spectre of a second wave of the disease worried the authorities.

The tally marked the highest in two weeks and infections outside the Seoul metropolitan area showed a sustained increase, the Yonhap news agency reported.

South Korea was praised for containing its first outbreak of Covid-19 but Asia's fourth-largest economy has experienced persistent outbreaks in recent weeks, mostly in the capital.

For the first time in almost two months, new daily cases from other cities surpassed those from Seoul area.

The south-western city of Gwangju has recorded more than 50 cases the past few days, prompting the suspension of operations at public facilities such as public libraries and museums.

"Gwangju City immediately upgraded its social distancing guidelines to second stage, limiting indoor gatherings to below 50 and outdoor gatherings to below 100," Prime Minister Chung Sye-kyun told a meeting on Friday.

Health authorities have recently categorised social distancing rules in three stages - stage 1 being the least intense and stage 3 the toughest, where schools and businesses are urged to close.

Earlier this week, two primary school students in Daejeon, a metropolis 164km south of Seoul, were tested positive after coming in contact with a peer.

Health authorities suspected one of the two to have been infected at the school. If confirmed, it would mark the first case of the virus being transmitted at a school in South Korea, according to Yonhap.

Schools were given the full go-ahead to hold offline classes in June, but some of them were forced to shut down due to sporadic cluster infections.

The country normally begins a new semester in March.

The recent spikes are concerning as new clusters are emerging in wide range of areas, making it harder for epidemiological surveys.

But with the case numbers still manageable, local governments will each decide whether to upgrade their guidelines, Vice-Health Minister Kim Gang-lip told a briefing.

The new cases took South Korea's tally to 12,967 with 282 deaths by midnight on Thursday.