LONDON — A graphic video of a public hanging in Iran of three men convicted for rape shows the "brutalisation" of the condemned and those who watch executions, Amnesty International said Thursday.

In the video, which the London-based human rights watchdog said it received from a blogger, the men are seen standing atop three buses as guards hook ropes around their necks from a bridge overhead.

Dozens of people can be seen watching from below in what was said to be Azadi Square in the western Iranian city of Kermanshah on Tuesday.

After the crimes for which the three men were convicted and their executions are announced, the buses back up one by one and leave the trio suspended by their rope as numerous onlookers photograph or film the hangings, Amnesty said.

"These latest public executions underline the continuing horror of the death penalty in Iran," said Hassiba Hadj Sahraoui, Amnesty's deputy director for the Middle East and North Africa.

"Not only those executed, but all those who watch public executions, including, children, are brutalised and degraded by the experience. These public displays of killing perpetuate a culture of acceptance of violence and blood lust, rather than a belief in justice," she said.

"We have also been informed that the arrest, trial and execution of these men took barely two months, which raises serious questions about the fairness of the trial."

Iran's ISNA news agency reported that three men convicted of rape were hanged Tuesday in Kermanshah, saying people who watched chanted slogans praising the judiciary for their action.

Amnesty said it received the footage from Fazel Hawramy of the website

So far this year, 171 people have been executed in the Islamic republic, according to an AFP tally based on media and official reports.

Iranian media reported 179 hangings last year but international human rights groups say the actual number was much higher, ranking Iran second only to China in the number of people it executed.

Tehran says the death penalty is essential to maintain law and order, and applied only after exhaustive judicial proceedings. Murder, rape, armed robbery, drug trafficking and adultery are among the crimes punishable by death in Iran.