Meanwhile, the governor of mountainous Qazvin province and at least five other people were killed Saturday as their helicopter crashed during an inspection of the earthquake-hit zone.

Governor Massud Emami, the provincial police chief, an aide to the governor, the pilot and two other passengers all died, state news agency IRNA said.

According to the student news agency ISNA, two journalists on the flight were also killed.

The helicopter was headed for Alamout to inspect the damage from Friday's killer quake, state television said.

There was no immediate word on the cause of the crash.

State media said the final death toll from the quake was expected to hover around 25, with hundreds more left injured or homeless in a string of villages in the Alborz mountain range in the provinces of Qazvin and Mazandaran.

Many of the dead were drivers caught in enormous rockslides while making the journey along the perilous mountain road linking Tehran with the Caspian Sea city of Chalus. On Saturday the key highway remained closed to traffic.

The second severe quake to hit Iran in less than six months struck at about 5:00 pm (1330 GMT) on Friday. Reports on its magnitude varied, but most said it measured at least 6.1 on the Richter scale.

Its epicenter was located in the Mazandaran province town of Baladeh, 70 kilometres (43 miles) north of Tehran, and Tehran University's Geophysics institute measured a further 65 aftershocks ranging from 1.6 to 5.5 on the Richter Scale.

Further strong jolts were felt in Tehran Saturday.

A number of scattered mountain villages in Qazvin province visited by an AFP reporter showed signs of severe damage to structures, with the Red Crescent already distributing tents.

But the quake also appeared to give a major psychological jolt to Tehran, especially as it came less than six months after a tremor of 6.7 on the Richter scale killed close to 26,000 people when it flattened the southeastern city of Bam.

"The earthquake was felt in Tehran, but it was from faultlines to the north," Mohammad Mokhtari, president of Tehran University's Seismology Faculty, told AFP.

"But we cannot guess what the consequences of it will be on the faultlines that are situated directly beneath Tehran," he added.

Tehranis are especially worried since experts have said a strong earthquake in the teeming capital -- built on top of four major faults -- could kill up to a million people. They cite congestion, the chaotic urban layout and shoddy construction of many buildings.

In addition, experts say a major quake is long overdue.

After people ran out into the streets in panic on Friday to the shaking of walls and shattering of glass, tens of thousands spent a part of the night outdoors.

"We spent some of the night outdoors. Finally at around three o'clock in the morning, we went into the house," one resident said.

Temblors of between 6.1 and 6.9 on the Richter scale can cause destruction in built-up areas up to about 100 kilometers (63 miles) from the epicentre.

Iran lies on some of the world's most active seismic fault lines, and quakes are common. During the 20th century, around 20 big quakes hit Iran, leaving more than 140,000 dead.

In the wake of the Bam quake, Tehran's mayor said an estimated two billion dollars was needed to modernise the sprawling city of some 10 million people in order to cope with a quake here.

He also identified hospitals, fire services, bridges, water reservoirs, bakeries and electrical pylons as areas of priority. So far, however, the concern has yet to translate into action.

TERRA.WIRE