HANOI - Two Chinese citizens in Vietnam have tested positive for coronavirus, Vietnam's health ministry said on Thursday, as the Southeast Asian country suspended flights to the Chinese city of Wuhan, where the new virus was first identified.

China has stepped up measures to contain a virus that has killed 25 people and infected more than 800, with public transport suspended in 10 cities, the shutting of temples and the rapid construction of a hospital to treat the infected. 

"The ministry of health will continue to monitor for suspected symptoms at airports in Nha Trang and Danang where, many Chinese visitors arrive," deputy health minister Nguyen Truong Son said in a ministry statement.

"All visitors from infected areas will be closely tracked and must undergo health checks".

The father and son pair were hospitalised on Wednesday after showing signs of fever and are being treated at the Cho Ray hospital in Ho Chi Minh City, the ministry said.

The father had recently arrived in Vietnam from Wuhan and had travelled to the Vietnamese capital Hanoi and the southern city of Nha Trang before being hospitalised.

Late on Thursday, the Civil Aviation Authority of Vietnam (CAAV) said it had suspended all flights between Wuhan and Vietnam, and ordered domestic airports to step up screening measures to detect possible fever-like symptoms in travellers.

Major tour operators in Vietnam said they had cancelled all tours to the central Chinese city, local media reported.

(Additional reporting by Phuong Nguyen; Writing by James Pearson; Editing by Angus MacSwan) ((james.pearson@reuters.com; +84-24-3825-9623;))