North Korea has announced that it is requiring all citizens to wear masks from October, citing the risk that the coronavirus and influenza could both spread from fall to winter.

An article in ruling party newspaper Rodong Sinmun on Tuesday called on people to take thorough anti-infection measures. It said it's now fall and the large difference in temperatures between day and night makes people more susceptible to viral respiratory illnesses.

It added that the World Health Organization and other experts are concerned that the flu and coronavirus could spread simultaneously.

North Korea declared victory over the coronavirus last month and said it would, in principle, remove mask requirements. But the country appears to be on guard again.

A man was seen wearing a mask as he rode a bicycle on the North Korean side of a river in the Chinese border city of Dandong on Saturday.

Earlier this month, North Korean leader Kim Jong Un disclosed plans to start a coronavirus vaccination program in an apparent move to keep public discontent in check.