TEHRAN, Iran - Iran has sentenced eight women and one man convicted of adultery to death by stoning, activists said Sunday.

A lawyer and women's rights activist, Shadi Sadr, said the nine, who are between 27 and 50 years old, were convicted of adultery in separate cases in different Iranian cities. Trial protocol was not applied properly in the cases, she said.

Six of the nine were convicted based solely on judges' decisions with no witnesses or the presence of their lawyers during their confessions, said Sadr, who has been leading a campaign in Iran against stoning deaths.

"Their verdicts are approved, and they may be executed at any time," she told reporters. "We are trying to stop the implementation of their verdicts. And we want to amend the country's penal law, in which death by stoning is prescribed."

Under Iran's Islamic laws, adultery is the only capital offense punishable by stoning. A man is usually buried up to his waist, while a woman is buried up to her neck. Those carrying out the verdict then throw stones until the condemned dies.

Stoning was widely imposed in the early years after Iran's 1979 Islamic revolution, but it has seldom been applied in recent years, though the government rarely confirms when it carries out stoning sentences.

Reformist legislators have demanded an end to death by stoning as a punishment for adultery, but opposition from hard-line clerics has sidelined their efforts.