The European Union on Friday added four Iranian officials to its sanctions blacklist over a crackdown on demonstrators, ahead of the first anniversary of the death of Mahsa Amini.

The 27-nation bloc has already imposed visa bans and asset freezes on around 170 Iranian individuals, companies and agencies over the repression.

The four officials targeted included a commander in Iran's Revolutionary Guard, two regional police chiefs and a prison boss.

Four prisons, a news agency associated with the Guards and the Supreme Council of Cyberspace, which monitors the internet, were also placed on the blacklist.

Amini, a 22-year-old Iranian Kurd, died on September 16 last year after her arrest in Tehran for an alleged breach of the Islamic republic's strict dress code for women.

Her death triggered months of nationwide demonstrations under the slogan "Woman, Life, Freedom".

In a statement, the EU's 27 nations said they "reaffirm their strong support for the fundamental rights of Iranian women and men and their aspirations".

"We continue to consider all appropriate options at our disposal to address any issues of concern," they said.