Iran on Sunday hanged three men found guilty of forbidden acts as well as two convicted rapists and a drug trafficker in prison of the southwestern city of Ahvaz, the ISNA news agency reported.

Three of the prisoners were hanged for committing forbidden acts against religion, the report said, convicted of unlawful acts and acts against Sharia law, based on the articles of 108 and 110 of the Iranian Islamic penal code.

Article 108 reads: Sodomy (or Lavat) is sexual intercourse between men. Article 110 says: Punishment for sodomy is killing; the Sharia judge decides on how to carry out the killing, according to the Iran Human Rights Web site.

The names of the three men have not been given -- only their initials M.T, T.T and M.Ch.

Human rights group have said the case is particularly poignant because gay men before the courts are usually charged with the more coercive crimes of sexual assault and rape, rather than two consenting participants.

Mahmood Amiry-Moghaddam, a researcher at Iran Human Rights, who is investigating the executions, told The Independent: Iranian authorities have previously presented such cases as rape, in order to make the execution more acceptable and to avoid too much international attention, but this time the news is not presented as rape.

This case is the only one in recent years where the only basis for the death sentence has been a sexual relationship between two men, with reference to the articles 108 and 110 of the Islamic Penal Code. These articles are very clear, Amiry-Moghaddam said.

The latest hangings bring the number of executions so far in Iran this year to 180, according to an AFP tally based on media and official reports.

Last year, Iranian media reported 179 hangings last year, but international rights groups say the number is much higher.

Daniel Brett, director of the Ahwazi Arab Solidarity Network told the Gay Middle East Web site: Ahvaz has the highest rate of executions in Iran, partly due to the persecution of the local Arab population and partly because prisoners from other parts of Iran are transported to the city - particularly the notorious Karoun prison where hangings are carried out in secret.