Hassan Nourian, Iran’s consul general in Karachi, said the fishermen, who are from Iran’s southeastern Sistan and Baluchestan Province, were freed following calls between Iranian and Pakistani officials.
Nourian said the Iranian nationals had entered Pakistani waters “by mistake” because they did not have navigation equipment.
He added that more Iranian sailors and fishermen are expected to be set free by Pakistan in the near future.
The consul general also said Iran has planed training courses for local fishermen to help them stay away from other countries' territorial waters.
IRNA reported on Monday that the released Iranians have flown to the capital Tehran.
According to Iran’s official news agency, the trio had been in a prison in Karachi for months. The report did not say when they had been apprehended.
Last year, more than 60 Iranian nationals held in prisons across Pakistan’s southern Sindh Province were released through diplomatic efforts and returned to Iran.