South Korea reported nearly 700 new coronavirus cases Wednesday, second-highest daily total since the beginning of the outbreak here in January, despite tightened antivirus restrictions in place nationwide.

Korea added 686 coronavirus cases -- 662 locally transmitted and 24 originating from overseas -- in the 24 hours ending Tuesday at midnight, according to the Korea Disease Control and Prevention Agency.

Wednesday’s daily case count is the highest ever apart from Feb. 29 when the daily tally reached a peak of 909 cases during the first wave of infections swept through a minor religious sect. The daily increase in infections hovered around 100 until early last month, but it neared 700 only in a month. The country has seen triple-digit gains in infections since Nov. 8.

Health authorities announced Wednesday measures to aggressively expand COVID-19 testing and secure hospital beds for confirmed patients.

As part of efforts to rein in the silent spread of the virus, the authorities said they would enable anyone to be able to seek testing at local testing clinics regardless of symptoms. The measures are in addition to the government’s plan to introduce a saliva test and expand antigen testing on high-risk populations to rapidly identify positive cases.

Amid mounting fears of a possible shortage of hospital beds, the authorities said they would secure 154 more beds for critically ill patients by the end of this year. Currently, there are 43 such beds available, they said.

Three more COVID-19 treatment centers admitting patients with mild or no symptoms will open this week to accommodate 570 more patients. Currently, 58 percent of beds are filled.

Of Wednesday’s locally transmitted cases, 79 percent were in Greater Seoul -- 264 in Seoul, 214 in Gyeonggi Province, which surrounds the capital, and 46 in Incheon. Outside the Seoul metropolitan area, 31 cases were posted in South Gyeongsang Province, 23 in North Chungcheong Province and 20 in Busan.

Transmission routes for 19 percent of the cases were unknown for the past two weeks as of Wednesday, according to the KDCA.

In Greater Seoul, Level 2.5 restrictions, the second-toughest in the country’s five-tier social distancing system, are in place, with gatherings of more than 50 people banned, indoor sports facilities closed and establishments such as malls, stores, internet cafes and theaters only open until 9 p.m. Indoor dining is banned at cafes all day and at restaurants after 9 p.m.

Of the 24 imported cases reported Wednesday, nine were detected at the border, while the other 15 were identified in individuals under mandatory self-quarantine in Korea. Eleven cases were from the Americas, eight cases were from Europe and five cases came from elsewhere Asia.

Twenty of those cases were in Korean nationals.

The number of COVID-19 patients in serious or critical condition here stood at 149, up from 134 a day earlier.

Four more people died from the virus, bringing the death toll to 556, with the overall fatality rate at 1.41 percent.

So far, of the 39,432 people confirmed to have contracted the new coronavirus here, 30,177 have been released from quarantine upon making full recoveries, up 527 from a day earlier. Some 8,699 people are receiving medical treatment while under quarantine.

The country carried out 31,919 tests in the past day. A total of 75,080 people were awaiting results.

By Ock Hyun-ju (laeticia.ock@heraldcorp.com)