Seoul, Dec 6 : South Korea on Sunday decided to raise its social-distancing rules in the Seoul metropolitan area to the second-highest level for three weeks amid a spike in new Covid-19 cases for the past month. The country's five-tier social-distancing regulations will be lifted to Level 2.5 for the next three weeks in the capital area, which covers Seoul, its surrounding Gyeonggi province and the western port city of Incheon, reports Xinhua news agency. The distancing guidelines had been elevated to Level 2 for two weeks from November 24 to December 7, but the virus spread had yet to be contained in the metropolitan region. In the latest tally, South Korea reported 631 new cases the past 24 hours, raising the total number of infections to 37,546. The daily caseload was the highest in over nine months since March 2, rising in triple digits for 29 days since November 8. Of the new cases, 253 were Seoul residents and 176 were people residing in Gyeonggi province. Incheon added 41 more cases. Prime Minister Chung Sye-kyun told the meeting of the Central Disaster and Safety Countermeasure Headquarters that the country was faced with the biggest crisis in fighting against the pandemic. Chung said situations in the metropolitan area got very serious, citing the daily number of infections in the capital area reaching a new high of 470 and about 70 per cent of new cases coming from the Seoul area for the past week. The Prime Minister urged people to refrain from gatherings and meetings, and thoroughly follow basic quarantine rules, such as wearing masks and washing hands. /IANS