BANGKOK — The Ministry of Health on Tuesday said six more cases of coronavirus infection were confirmed in Thailand, adding the total number to 25 since the beginning of outbreak in December.

Suwanchai Watthanayingcharoenchai, chief of the Disease Control Department, said four Thai and two Chinese nationals were found to test positive for the novel strain of coronavirus, with one of them being in serious condition.

As for Thai patients, Suwanchai said two of them are couples returning from a trip to Japan, while the rest are a taxi driver and a private chauffeur in the resort town of Hua Hin in Prachuap Khiri Khan province. He did not identify which region where Chinese nationals came from.

Japanese authorities have been notified of the infection, Suwanchai added.

Seventeen infected patients are being treated at hospitals, while eight of them have recovered, including a 73-year-old Thai woman, health officials said.

In a related development, Suwanchai said Thai experts are working with South Korean counterparts to investigate a Korean patient who has been found to be infected with coronavirus after returning from a trip to Thailand.