South Korea is expected to send chartered flights to the coronavirus-hit Chinese city of Wuhan on Thursday night to airlift its nationals from the area placed under a lockdown, a foreign ministry official said.

It would represent an hourslong delay from Seoul's original plan to evacuate around 700 South Koreans seeking to leave the epicenter of the deadly contagious virus by beginning to send in planes early Thursday.

Two Korean Air planes were initially scheduled to take off at 10 a.m. and at noon, respectively, as part of the government's evacuation plan announced earlier this week under which two more flights were set to fly to the city Friday.

"There has been a change of schedule for chartered flights that were going to operate, and we have sent an urgent message to our citizens who were supposed to board the planes," a foreign ministry official said.

The official did not give details about the reason for the delay.

"We are consulting with the Chinese government to make sure that our citizens staying in Wuhan can return home as soon as possible according to the changed schedule," the official said.

The official said that the chartered flight will depart later Thursday, though he did not provide the exact departure time.

He added that there could be a possibility that only one of the two planes could fly on the day due to the delay but emphasized that the number of people on the evacuation list will not change.

The South Koreans consulate general in Wuhan notified the Koreans of the change of the changed flight schedule at about 1 a.m. (local time) and asked them to wait until further notice.

The Korean residents in Wuhan had been told to gather at an airport in the city about five hours before the initial flight schedule.

South Korean officials have been in consultations with China on logistical details regarding the emergency transfer of its citizens.

On Tuesday, Seoul announced the plan to airlift its nationals out of Wuhan, after Beijing placed the city under lockdown, suspending flights and transportation there and in its surrounding regions amid the fast spread of the disease.

Seoul has been going all-out to stem the spread of the pneumonia-like illness that has killed 170 and infected over 7,700 in China alone.

South Korea has reported four confirmed cases of the virus infection since early last week, with no fatalities so far. Health authorities are tracking some 3,000 individuals who flew from Wuhan between Jan. 14 and 23, considering the disease's 14-day incubation period.

The government said the evacuated people will be put into isolation at two different public facilities in Asan, South Chungcheong Province, and Jincheon, North Chungcheong Province, in the country's central region.

But the quarantine plan has drawn strong opposition from the residents in the areas worried about potential infection. Some residents in Asan staged sit-in protests, blaming the government for making the decision without their consent.

Scuffles broke out late Wednesday as some angry residents in Jincheon threw water bottles and paper cups at government officials, including Vice Health Minister Kim Gang-lip, who had come to brief them on the plan and ask for their understanding.

Of about 700 people who have applied for the transfer, those with no symptoms will be transported first, and they will be subject to a quarantine check right before and after the flights, and will stay at the facilities for at least 14 days, according to the government. (Yonhap)