The measure, ordered by President Mohammad Khatami, was taken in and around the towns of Masjed Soleiman, Izeh and Baghmalek -- situated around 450 kilometres (280 miles) southwest of Tehran in Khuzestan province.

The report said a succession of tremors, measuring between 2.7 and 4.9 on the Richter scale, had jolted the area since early Tuesday.

Iran has been on a quake footing after a massive earthquake hit the southeastern city of Bam on December 26, killing up to 35,000 people.

"The president has given the order to the concerned services to be on maximum alert and we are very worried," Masjed Soleiman's prefect, Sattar Akbarzadeh, told state television.

The official also warned that in Masjed Soleiman there was a major risk of potentially explosive leaks from the vast oil and gas field underneath the city.

He nevertheless called on residents to "remain calm", while revealing that overnight "people had been sleeping on the streets or in prepared areas even though there was heavy rain" and appealed for 20,000 tents.

"All administrative services in the province have been placed on maximum alert," Shapour Rostami, an official from the provincial natural disasters unit, also told state television.

"We have prepared three camps around the towns of Masjed Soleiman, Izeh and Baghmalek, and all schools have been closed," he said.

"All facilities in the three towns have been mobilised, and all facilities in the province are ready to be sent there if needed."

Masjed Soleiman was last hit by a major quake in September 2002, when an earthquake measuring 5.5 on the Richter scale caused five injuries.

The Bam quake has also prompted the Islamic republic's clerical leaders to consider proposals to shift the political capital out of quake-prone Tehran, which sits on several major seismic faultlines.

Hassan Rowhani, a top cleric, said the Supreme National Security Council which he heads would "seriously study the problem of moving the capital" in a meeting on Saturday.

During the 20th century, around 20 big quakes hit Iran, leaving more than 140,000 people dead. Since 1991 alone, and before the Bam disaster, nearly 1,000 earthquakes have claimed some 17,600 lives and injured 53,000 people, according to official figures.

TERRA.WIRE