Two of the men, identified only as P.D. and M.M., had been found guilty of smuggling 36.5 kilogrammes and 40 kilogrammes of heroin respectively, the news agency said.

The third man, identified as V.A.R., was convicted of smuggling 15 kilogrammes of opium and 14.5 kilogrammes of heroin.

The latest hangings took to at least 223 the number of executions in Iran this year, according to an AFP count.

Amnesty International says Iran carried out more death sentences in 2007 than any other country apart from China, executing 317 people.

Capital offences in the Islamic republic include murder, rape, armed robbery, drug trafficking and adultery. -- AFP