Iran says a moderate earthquake has rattled a town in north Iran on the Caspian Sea.

The semiofficial Fars news agency says the quake hit Sari in the densely populated Mazandaran province, about 265 kilometres northeast of Tehran, around 20:44 local time (17:14 GMT) yesterday.

It said there were no reports yet on possible casualties or damage, but it was also felt in nearby towns.

Iran says the strength of the quake was 5.2 on the Richter scale, considered moderate.

The country is located on seismic fault lines and is prone to earthquakes, experiencing at least one slight quake a day on average.

In 2003, some 26,000 people were killed by a magnitude 6.6 quake that flattened the historic south-eastern city of Bam.