Archaeologists in China have uncovered more than 3,000 dinosaur footprints, state media reported, in an area said to be the world's largest grouping of fossilised bones belonging to the ancient animals.

The footprints, believed to be more than 100 million years old, were discovered after a three-month excavation at a gully in Zhucheng in the eastern province of Shandong, the Xinhua news agency reported.

The prints range from 10 to 80 centimetres in length, and belonged to at least six different kinds of dinosaurs, including tyrannosaurs, according to the report.

Wang Haijun, a senior engineer at the Chinese Academy of Sciences, said the prints faced the same direction, Xinhua said.

This indicated a possible migration or a panic escape by plant-eating dinosaurs after an attack by predators, added Mr Wang.

Archaeologists have found dinosaur fossils at some 30 sites in Zhucheng, known as "dinosaur city".

The region has seen two major digs since 1964, and experts say the discovery of so many dinosaurs in such a dense area could provide clues on how the animals became extinct millions of years ago. Plans are being made to set up a fossil park in the area.