Beijing (AFP) - Thrill-seeking tourists in China got more than they bargained for when cracks appeared in a glass-bottomed walkway suspended 1,080 meters (3,540 foot) over a canyon, reports said.

Images showing small cracks in the "skywalk" built around a mountain, which opened just two weeks ago, spread on social media along with doubts over its safety.

"When I was almost at the end (of the walkway), there was a sudden loud bang and a tremor beneath my feet," the state-run China Net cited one woman as saying on Tuesday.

The cracks resembled "winter frost on a window pane", the report said, and were apparently caused by a dropped stainless steel cup.

But the incident at Yuntai mountain in the northern province of Henan "doesn't affect safety", park officials were quoted as saying.

The glass made up of three layers is supposedly capable of supporting up to 800 kilograms (1,763 pounds) per square metre, they said.

The incident occured during China's hectic week-long national holiday period, when tens of millions take pleasure trips.