Nine people have been denied entry into South Korea after they handed in “substandard” certificates as proof of a negative COVID-19 test result, health authorities said Tuesday.

Since the country tightened entry rules on arrivals from “high-risk” countries in mid-July, 22 people have arrived with a coronavirus-free certificate but were later diagnosed with COVID-19 here, it added.

Between July 13 and Aug. 3, a total of 548 people arrived from Bangladesh, Pakistan, Kazakhstan, Kyrgyzstan, the Philippines and Uzbekistan -- the six countries designated as being high-risk, according to the Korea Centers for Disease Control and Prevention. Of them, 512 submitted a certificate proving they had tested negative for the coronavirus. The remaining 36 were mostly transit passengers, except two infants.

Of the 512 people, 22 tested positive for the virus -- 18 during the screening process at the border and four while under mandatory self-quarantine -- according to the KCDC.

Currently, the government requires international arrivals from six countries with a high infection rate to submit the certificate. The list of high-risk nations is revised on a regular basis.

Korea reported 34 new COVID-19 cases Tuesday -- 21 imported cases and 13 locally transmitted. The country’s total caseload as of Tuesday was 14,423.

Two more cases were reported in connection with a franchise coffee shop and restaurant in southern Seoul. The initial patient visited the cafe on July 22 and then a restaurant a day later, infecting 11 others so far.

The initial patient from the coffeehouse cluster did not properly wear a mask at the coffee shop and restaurant, KCDC Deputy Director Kwon Jun-wook said at a briefing Tuesday.

The new cluster of infections appears to be linked to another cluster at a camping site in Hongcheon, Gangwon Province, according to the initial epidemiological study. One of the persons who went on a camping trip there was found to have been at the cafe for about 30 minutes on July 22 while the initial patient was there. How the virus spread between the two, who were about 3 meters apart at the cafe, has yet to be identified.

One more soldier tested positive for the coronavirus, bringing the total number of cases linked to a military base in Pocheon, Gyeonggi Province, to 22.

Of the locally transmitted cases, six were registered in Seoul, three in Gyeonggi Province, and one each in Busan, Incheon, Gwangju and North Gyeongsang Province.

The number of daily new local infections was in the single digits for the past three days, with eight on Saturday, eight on Sunday and three on Monday.

Some 65 percent of COVID-19 cases have come in from overseas for the past two weeks. The sources of infection for 6.4 percent of the cases were unidentified during the period.

Of Tuesday’s 21 imported cases, seven were Korean nationals. Seven of the 21 were detected during the quarantine screening process at the border, while the rest were identified while under mandatory self-quarantine in Korea.

Of the imported cases, 11 were from the Americas -- nine from the United States and two from Mexico -- and six were from Asia -- two from Russia, two from Uzbekistan, one from Kazakhstan and one from Bangladesh. Four cases were from Africa – one each from Egypt, Sudan, Ethiopia and Senegal.

Meanwhile, students infected with the novel coronavirus or in self-quarantine will still be able to take the upcoming college entrance exam scheduled for Dec. 3, authorities announced Tuesday.

According to the plan unveiled by the Ministry of Education, students infected with the virus will take the test at hospitals or other government institutes. Those in self-quarantine should travel by car or ambulance to take the exam in separate testing sites.

The ministry also said that 1,185 testing sites will be set up to hold a maximum 24 students per testing room, down from the usual 28, to ensure physical distancing among students. Desks will be installed with plastic dividers and face masks will be mandatory.

So far, 13,352 people, or 92.57 percent, have been released from quarantine upon making full recoveries, up 21 from a day earlier. Some 770 people are receiving medical treatment under quarantine. Thirteen people remain in serious or critical condition.

One more person died Tuesday morning, raising the death toll to 302. The overall fatality rate stood at 2.09 percent -- 2.44 percent for men and 1.79 percent for women -- as of Monday.

The country has carried out 1,589,780 tests since Jan. 3, with 18,724 people awaiting results as of Monday.

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