Iran has “dramatically” escalated its crackdown on freedom of expression ahead of this week's parliamentary election, Amnesty International said in a report published on Tuesday.

The report entitled "We are ordered to crush you: Expanding Repression of Dissent in Iran" details repressive acts by the Iranian authorities since February 2011, including a recent wave of arrests.

The arrests, Amnesty said, have targeted lawyers, students, journalists, political activists and their relatives, as well as religious and ethnic minorities, film-makers and people with international connections, particularly to media.

"In Iran today you put yourself at risk if you do anything that might fall outside the increasingly narrow confines of what the authorities deem socially or politically acceptable," said Ann Harrison, interim deputy director of Amnesty's Middle East and North Africa programme.