Iran's opposition leader Mirhossein Mousavi said on Thursday he was determined to continue fighting against "major" presidential election rigging despite pressure to stop, his website reported.

"I am pressured to abandon my demand for the vote annulment ... a major rigging has happened ... I am prepared to prove that those behind the rigging are responsible for the bloodshed ... Continuation of legal and calm protests will guarantee achieving our goals," Mousavi said.

He said the nation had the right to protest over the disputed presidential vote.

"I insist on the nation's constitutional right to protest against the election result and its aftermath ... I strongly criticise the closure of the Kalameh-ye Sabz daily and arrest of those who worked there ... The illegal confrontation with the media opens the way for foreign interference," he said in a statement.

Mousavi was the managing-director of the Kalameh-ye Sabz daily, which was closed earlier this week.

"Such illegal behaviours (closure of the newspaper) unfortunately will lead society to get information from foreign media," said Mousavi. - Reuters