In Iran the death sentence is usually handed down for crimes such as murder, rape, homosexuality and until recently drug-related offences. The hangings usually take place in the early hours of the morning as the sun rises, often at the crime scene or in a city centre.
The families of both the victims and convicts gather as the authorities prepare to hang the condemned criminals from cranes.
Under Iran's sharia law, the victim's family has the right to spare the convict from execution for certain crimes such as when someone is convicted of killing another person in a car accident. This means many executions see the convict's relatives incessantly pleading for a pardon.
A huge crowd, which might include children, usually surrounds the scene, such as in this video.
When Iranian authorities last year lifted a ban on photographing public executions, an Iranian photo-journalist, Ebrahim Noroozi, began to freely document them. For those pictures, he won a prize in the contemporary issues category of the 2012 edition World Press Photo in April this year.
"I don't go to executions for fun. As a journalist I don't want to pass judgment on whether they are good or bad, but the act itself disgusts me," he told the Times.
According to Amnesty, at least 676 judicial executions are known to have been carried out in 2011 globally. More than half of those took place in Iran, which executed at least 360 people. But reports about the regime's campaign of secret and mass hangings of prisoners have made it impossible for Amnesty to publish the true figures in Iran, like in China.