Iranian authorities raided and shut down the office of a human rights group led by Nobel Peace Prize winner Shirin Ebadi on Sunday as the group was preparing to present an award to a political activist who spent 17 years in prison in the Islamic republic.

Iranian authorities banned Ebadi's Center for Protecting Human Rights last year, but it has continued to operate from an office in the north of the capital, Tehran.

Ebadi said police in uniform and plainclothes security officials sealed the building where her group was working without presenting a warrant. No arrests were reported.

The prominent activist said her group would continue its work despite the raid.

"Shutting down our offices won't make us stop our human rights activities. We will meet again somewhere else and will continue to support the rights of activists and political prisoners," she told The Associated Press.

Ebadi said recent reports by her group accusing the Iranian government of human rights violations might have prompted the crackdown. She said U.N. human rights representatives are not allowed to visit Iran but have seen the group's reports and subsequently condemned what they called gross human rights violations.

In an annual report in May, Ebadi's group said "freedom of speech and freedom of circulating information have further declined" since hard-line President Mahmoud Ahmadinejad took office in 2005.

Among her group's work, it has campaigned for judicial reforms such as banning stoning and cutting off limbs as punishments for convicted criminals. It has also campaigned against executions of juvenile offenders.

Ebadi said the building authorities targeted Sunday was bought with money she received after winning the Nobel Peace Prize in 2003.

Ebadi, a lawyer and human rights and democracy campaigner, won the prize for efforts that included promoting the rights of women and children in Iran and worldwide. She is the first Iranian and Muslim woman to win the award.

"We will remain committed to defending the rights of defendants jailed for their political views and beliefs," she said.

Taqi Rahmani, who spent a total of 17 years in jail after Iran's 1979 Islamic revolution, could not get the award Sunday but Ebadi said her group will honor him later.

Rahmani, 48, spent more than a third of his life in prison on vague charges of seeking to overthrow the ruling Islamic establishment. In 2005, Rahmani received an award from Human Rights Watch in recognition of the 17 years he spent imprisoned for his views.

Besides honoring Rahmani, Ebadi's group had planned Sunday to mark the 60th anniversary of Human Rights Day.