Tasnim � One day after a 6-magnitude earthquake destroyed some rural structures in Iran�s southeastern province of Kerman, a number of subsequent tremors have been shaking the region, the biggest of which occurred on Saturday morning.

The biggest earthquake of Saturday, measuring 5.1 on the Richter scale, occurred at 10:47 UTC at a depth of 10 km in an area 58 km northeast of the provincial capital, Kerman, according to the United States Geological Survey (USGS).

Aftershocks in the wake of the Friday morning�s 6-magnitude earthquake have raised concerns in the region. No casualties were reported in that quake, which destroyed a number of houses in rural areas, caused power cuts and forced people to remain outdoors.

The closest cities to the quake center were Kerman, Zarand, and Ravar.

Kerman is an old historical city with a population of more than 3 million.

The quakes in Kerman follow a massive temblor that hit Kermanshah in west Iran on November 12, killing more than 480 people and injuring around 10,000 others.

Iran is one of the most seismically active countries in the world, being crossed by several major fault lines that cover at least 90% of the country.

The deadliest quake in Iran�s modern history happened in June 1990, devastating many areas in the northern province of Gilan and killing around 37,000 people.

In 2003, a magnitude 6.6 earthquake in the province of Kerman flattened the historic city of Bam, killing more than 26,000 people.