Chinese residents rushed out of doors to marvel a rare astronomical illusion of "triple suns" in the sky over Chifeng, in north China's Inner Mongolia Autonomous Region Friday morning.

The sun accompanied by two smaller twins suddenly popped up in the sky at around 09:00, and the triple appeared surrounded by an arched rainbow-like halos.

The astronomical illusion hang across over Chifeng for around two hours, and many residents took pictures or videos to record the magical moment out on the streets.

Some could even see five suns shining in some area of the city.

"I've got a lot of phone calls coming in from home and my friends when working in that building. They told me to go out and see the triple suns. So I rushed out to have a glimpse of them," said Zhou Lu, who was taking pictures of the suns along the roadside.

The illusion is actually deemed as a legitimate astronomical phenomenon which is also known as phantom sun or ice halo, according to the Chifeng Meteorological Bureau.

It only appears when ice crystals create high clouds in the air around 6,000 meters above ground, and produce reflected sunlight.

"The cause of such phenomenon lies in the existence of the stratocirrus consisting of ice crystals in the air, and sunlight is reflected by the crystals into such an illusion," said Chang Xin, a forecaster in Chifeng Meteorological Bureau.