Mehdi Karroubi, a major opposition leader in Iran, was reportedly attacked at a rally marking the 31st anniversary of the Islamic Revolution, his son told UK's BBC.

Karroubi's son Mohammad Taghi Karroubi, told BBC Persian TV his father's face was burnt and his eye injured.

They sprayed tear gas into my father's face, burning him, and he was also hit on the head with a stone, Mohammad said. He also said that a window of his father's car had been broken. The politician is now at home under medication and the supervision of a doctor, his son said.

Iran's opposition reported clashes on the anniversary of the revolution, alleging that security forces attacked anti-government protesters.