Seoul/Beijing, Feb 1 : China resumed mandatory Covid-19 tests for arrivals from South Korea on Wednesday, in its latest tit-for-tat response over Seoul's strengthened anti-virus curbs against travellers from the neighbouring nation. In a notice sent on Tuesday to airlines operating between the two countries, Chinese aviation authorities said all passengers on board direct flights from South Korea to China will receive polymerase chain reaction (PCR) tests on arrival from Wednesday, Yonhap News Agency reported citing officials and sources as saying. Those who test positive are required to be quarantined or hospitalised. It is the latest in a series of retaliatory measures targeting South Korea after Seoul tightened curbs on travellers from China last month due to the fast spread of new cases in the neighbouring country. Last month, China scrapped its previous requirement of mandatory PCR tests on all international arrivals. Seoul's Embassy in Beijing said it was informed by the Chinese government of the new regulation for travellers from South Korea only. Chinese Foreign Ministry spokesperson Mao Ning said in a regular press briefing on Tuesday that there needs to be corresponding and "equivalent measures", voicing concerns over what it called Seoul's "discriminatory" entry restrictions. A Seoul Foreign Ministry official said China should not restrict people's entry across its border for reasons other than those of pandemic response measures. /IANS