The London-based human rights group, Amnesty International has expressed alarm at the recent killings in Iran of two prominent government critics.

Dariush Foruhar and his wife were found stabbed to death at their home in Tehran two weeks ago.

Police have arrested a number of suspects in connection with the killings.

But Amnesty says attacks against government critics have rarely been subject to impartial and open investigation, and has called for an independent inquiry.