The six sailors arrived in Tehran via an Iran Air flight on Thursday after diplomatic efforts by Iran’s Consulate General in Karachi and with the assistance of local authorities.
The Iranian nationals had been held in custody in Pakistan for several months after the Pakistan Coast Guards detained them on charge of illegally entering Pakistani territorial waters.
The sailors, however, have been denying the charge, saying they had been arrested in international waters.
It was the fourth group of Iranian sailors released from Pakistan over the past two years.
Iran and Pakistan signed an agreement on the extradition of criminals in May 2014.