This is the eerie moment huge swarms of insects darkened skies around a city in China.

The creepy footage shows giant columns of the bugs - thought to be either mosquitos or midges - rising into the air along a roadside in Taiyuan, Shanxi Province, on May 7.

In the video, as the camera pans around, the towering lines of the insects carry on for as far as the eye can see.

The incident was reported online by Sichuan Observation and posted by Chinese internet group Sina. An online story posted on May 8 shows a different video of the same incident, which it confirms occurred on the previous day. Translated into English, the article's headline reads: "Taiyuan witnesses a swarm of mosquitoes and insects extending for several kilometres."

Recent heavy rains may also have triggered a sudden surge in mosquito numbers.

Mosquitoes are best known for their annoying buzzing sound and their painful bites. Mosquitoes are also vectors for many diseases, including malaria, dengue fever, and yellow fever. Midges on the other hand can be biting or non-biting.

This is the eerie moment huge swarms of mosquitos darkened skies around a city in China.

The creepy footage shows giant columns of the blood-sucking bugs rising into the air along a roadside in Taiyuan, Shanxi Province, on May 7.

As the camera pans around, the towering lines of the menacing mozzies carry on for as far as the eye can see.

Local media reported that the strange phenomenon stretched for more than three kilometres (1.8 miles). There were believed to be tens of thousands of the bugs.

Some locals blamed a mass breeding frenzy along a local Fen River, a tributary to China's famous Yellow River.

While others suggested the theory of climate change for the baffling freak of nature.

Recent heavy rains may also have triggered the sudden surge in mosquito numbers.

Mosquitoes are best known for their annoying buzzing sound and their painful bites. Mosquitoes are also vectors for many diseases, including malaria, dengue fever, and yellow fever.