MANILA - The Philippines' health department has traced 22 out of 26 South Koreans who arrived last week in Cebu from virus-stricken Daegu City, an official said Sunday.

• DOH tracing Koreans who landed in Cebu amid COVID-19 spread in SoKor

Twelve of the tourists have been placed under self-quarantine in Cebu, while 10 have returned to South Korea, according to Health Assistant Secretary Maria Rosario Vergeire.

The whereabouts of the remaining four are continuously being ascertained by local authorities.

Vergeire said that so far, none of the visiting South Koreans have exhibited symptoms of the coronavirus disease 2019 (COVID-19).

The number of COVID-19 cases in South Korea has swelled to over 3,500 on Sunday, most of which were recorded in Daegu City located south of the capital Seoul. It has the highest number of infections outside of China where the new strain of virus is believed to have originated.

The tourists arrived in the country last Wednesday just as government announced it would not be allowing travelers from Daegu and the rest of South Korea's North Gyeongsang province to enter the country.

• Philippines mulls wider travel ban on virus-hit South Korea

Meantime, health officials are monitoring 30 other persons considered as patients under investigation who are admitted in hospitals across the country, Vergeire said.

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"Binabantayan po ng Pilipinas hindi lang yung sitwasyon within the country. Tinitingnan din po natin what’s happening outside of the country para alam po natin paano tayo magre-respond," she told radio DZMM.

(The Philippines is monitoring not only the situation within the country but also what's happening outside so we know how we will respond.)

The country has yet to record a local transmission of the disease, which Health Secretary Francisco Duque credited to the public's vigilance and government's prompt response.

• Vigilance, strict protocols keeping PH safe from local transmission of coronavirus

The Philippines has recorded three COVID-19 cases, all imported in nature, involving Chinese nationals who came from the Chinese City of Wuhan. One died while the two others have recovered and returned to China.