At least four people were killed and 120 injured Tuesday in a 4.9 magnitude earthquake that hit Iran's northeastern city of Kashmar, state media reported.

The quake struck at 1:24 pm (0954 GMT), Kashmar's governor, Hajatollah Shariatmadari, who gave the casualty toll, said on state television.

Thirty-five people were hospitalised, he said, adding the quake damaged mostly dilapidated buildings in urban and rural areas of the city.

State television aired footage of the aftermath of the quake showing first responders working in a street where all buildings were reduced to rubble.

The United States Geological Survey said the earthquake hit at a depth of 10 kilometres (six miles).

Iran sits atop various tectonic plates and is often hit by earthquakes.

A 5.9 magnitude quake early last year killed three people and injured over 800 in the country's mountainous northwest, near the border with Turkey.

And in one of the world's deadliest disasters, a 6.6 magnitude earthquake killed over 31,000 people in Iran's southeastern city of Bam in 2003.