At least four people were killed and 20 others were injured when a 5.9-magnitude earthquake hit northwestern Iran early on Friday, Iranian media reported.

The report says the quake hit at 2:20 am Friday in Iran’s East Azarbaijan province. It says the temblor occurred at a depth of two kilometers (1.2 miles).

The US Geological Survey puts the quake’s magnitude at 5.8 at a depth of 10 kilometers (6.2 miles).

A magnitude 5 earthquake can cause considerable damage.

Iran is located on major seismic faults and experiences one earthquake a day on average. In 2003, a magnitude 6.6 earthquake flattened the historic city of Bam, killing 26,000 people.