The epicentre of the quake was measured at 85 kilometres (52 miles) southeast of the southern town of Minab at 0208 GMT, the USGS said in a statement. It was at a depth of 36.44 km.
Head of Iran’s Red Crescent rescue corps Mahmoud Mozafar told the Fars news agency that at least 11 people had been injured in five villages which were “severely” hit by the quake.
The Mehr news agency, quoted him as saying that “several houses were levelled” based on preliminary reports.
The reports said rescue teams were dispatched to the affected area.
The USGS said there was a 35 percent chance of fatalities from the quake which the Hong Kong Observatory measured at 6.1 magnitude.
Iran’s Seismological Centre has registered a series of aftershocks, measuring between 4.1 and 5.2.
Iran sits astride several major fault lines and is prone to frequent earthquakes, some of which have been devastating.
Last month, the biggest earthquake to hit the country in 50 years, measuring 7.8, killed a woman and injured more than a dozen other people in the southeast.
At least 40 people were killed across the border in Pakistan where hundreds of mud homes were levelled.
A double earthquake, one measuring 6.2 and the other 6.0, struck northwestern Iran last August, killing more than 300 people and injuring 3,000.
In December 2003, a massive quake struck the southern city of Bam. It killed 26,271 people — about a quarter of the population — and destroyed the city’s ancient mud-built citadel.
Channel News Asia