Two of the dead in the clashes in the town of Samirom, in Isfahan province, were police officers, officials said.

Television pictures from Samirom - 530 kilometres (330 miles) south of the capital Tehran - showed gutted houses, burned-out cars and streets littered with stones and broken glass.

According to the Associated Press news agency, demonstrators were apparently concerned that government plans to transfer districts from wealthy Samirom to its poorer neighbour, Shahreza, would have negative economic implications.

However an unnamed provincial official told Reuters news agency that tribal enmities had been enflamed by the proposed new administrative zones which would cut one group off from allies in a region where tribesmen often carry weapons.

Isfahan officials said later that the decision to re-organise the boundary had been put on hold and that a committee had been formed to look into the causes of the incident.

Sunday also saw peaceful demonstrations against similar boundary proposals in the north-eastern province of Khorasan.

Violent opposition

Two of Sunday's deaths eight deaths were police officers attempting to restore order in the trouble which began on Saturday night.

Officials quoted by the Iranian students' news agency ISNA quoted officials as saying just under half of the 150 injured were members of public and the rest policemen.

Several people were arrested on Sunday but later released.

A senior Isfahan official, Mehdi Taheri, said the offices of the Samirom governor had sustained damage in the rioting.