Image caption The counties in Ohio where the attacks took place make up one of the largest US Amish communities

Police in the US state of Ohio are investigating a rare violent feud in the Amish community, in which members have had beards and hair cut off.

Spiritual differences were said to be behind the attacks on more than half a dozen men and women, said police.

The investigation is being hampered by Amish reluctance to seek police help.

The tiny American Christian group, who call themselves the Plain People, generally shun modern conveniences such as electricity, televisions and cars.

Amish people rejected by the mainstream community are suspected of having carried out the attacks.

'Extremely rare'

Over the past three weeks, at least six men and women have been assaulted in four different counties, losing their beards or, in the case of the women, clumps of their hair.

You see this crime being committed, and I'm sitting here with my hands tied Sheriff Fred Abdalla

The victims have included a 13-year-old girl and a 74-year-old man.

The BBC's Paul Adams in Washington says one man was dragged from his home by the beard before his attackers tried to cut it off.

In religiously conservative Amish communities, women do not cut their hair and men grow beards only after they marry.

The attacks appear to target cherished symbols of Amish identity, our correspondent says.

He says that what makes them so baffling is that the attacks have been carried out by fellow Amish, apparently members of a particular clan from the town of Bergholz in rural eastern Ohio.

A 57-year-old woman in Trumbull County told police her sons and a son-in-law had cut her hair and her husband's beard last month. She claimed the estranged family members were involved in a cult.

The feud is thought to involve 18 Amish families, most of whom are said to be related.

Sheriff Fred Abdalla said some of the suspects had previously come to the attention of police after a threat against him, and a conviction of sexual contact with a minor.

He added that no charges had been brought and the investigation was moving slowly because of Amish reluctance to seek police help.

"You see this crime being committed, and I'm sitting here with my hands tied," the sheriff said. "I can't do a thing."

Attacks have taken place in Carroll, Holmes, Jefferson and Trumbull counties, regions heavily populated by Amish.

Professor Donald Kraybill, an Amish expert at Elizabethtown College, Pennsylvania, told the Associated Press news agency that Amish-on-Amish violence was "extremely rare."