GENEVA - Western countries on Thursday voiced concern at the rising number of executions in Iran as well as the "treatment of women as second class citizens" there.

Envoys from Canada and Portugal, the latter speaking on behalf of the European Union, criticised the Islamic Republic at a session of the United Nations Human Rights Council.

Canada's John Von Kaufmann said Iran's "deteriorating human rights situation" contravened its obligations under both international and domestic laws.

"Canada is concerned by the treatment of women as second class citizens under Iranian law and the suppression of peaceful demonstration in support of women's rights," he added.

Relations between Iran and Western nations are strained over the country's nuclear programme which the West suspects is a cover for developing atomic bombs. Iran says the programme is peaceful and designed to produce energy.

U.N. High Commissioner for Human Rights Louise Arbour said she had urged Iranian officials in talks in Tehran last week to ensure the right to peaceful public expression, and had raised the subject of the execution of juveniles.

Iran, which is not a full member of the Human Rights Council, routinely dismisses allegation it is violating human rights, accusing the West of double standards.

The number of executions in the country, many in public, has risen since July with the launch of a summer crackdown on what Iran calls "immoral behaviour".

Murder, rape, adultery, armed robbery, apostasy and drug smuggling are all punishable by death under Iran's sharia law, imposed after the 1979 Islamic revolution.

The official IRNA news agency on Thursday said that Iran had hanged three people convicted of involvement in a bombing attack in its oil-rich southwest.

Amnesty International, which says Iran has one of the highest rates of executions in the world, last week said it had recorded 210 so far this year, against 177 for all of last year.

Portugal's envoy, speaking on behalf of the 27-member EU, said: "We are very concerned with the human rights situation in Iran, in particular with the rising number of executions."

In a speech to the Council, Arbour also said that serious crimes including murder were going unpunished in the Democratic Republic of Congo.

No Congolese officials had been arrested or brought to justice for crimes committed there in the first six months of 2007, she added.

Her office in July issued a report accusing Congolese soldiers and police of having used "excessive and indiscriminate lethal force" to quash clashes in western Bas-Congo province, where 105 people were killed last Jan. 31 and Feb. 1.