More than 100 people were injured when a 5.7-magnitude quake struck northwestern Iran Friday, the state-run Press TV reported.

The quake jolted the Torbat-e-Heydarieh city in Khorasan Razavi province around 06.20 p.m.

The Iranian Seismology Centre said the epicentre was located seven kilometres outside the city.

City governor Mojtaba Sadeqian said 110 people were injured and about 80 percent of the houses in the city were damaged.

'There were no immediate reports of any fatalities. However, it is believed that a large number of people are trapped under the rubble,' Sadeqian added.

Torbat-e-Heydarieh is located 140 km from Mashhad, the provincial capital. It has a population of about 400,000.