A police force in the United States has gone viral after warning locals of “large boulder the size of a small boulder” blocking a highway.

The apparently paradoxical description was given by the San Miguel Sherriff’s Office to a rocky mass diverting traffic in Telluride, Colorado.

The supposedly dual-sized stone took the internet by storm, with the post shared tens of thousands of times in less than 24 hours.

“I think we should be grateful it wasn’t a large boulder the size of a large boulder,” replied US politician Rob Anderson.

Other Twitter users had questions.

“Did… did a self-conscious small boulder write this?” asked one.

Another, @pablo_honey1, posed: “Who would win in a fight? A large-boulder-sized small boulder or 20 small-boulder-sized large boulders?”

“We shall name it…..Biggie Smalls,” wrote a fellow Twitter user.

San Miguel Sherriff’s office later clarified that the rock was “approximately four feet (1.2m) across and weighed about 10,000lbs (4,500kg)”.

It added that there were no injuries or vehicle damage caused by the rogue object and the road’s eastbound lane was blocked for about 30 minutes until a snow plough cleared it.