Iran has received 14 sailors released by extremist group Al Shabab after protracted negotiations to secure their freedom.
Some of the men had been held for as long as eight years, Iranian media reported.
It remains unclear how Tehran secured their release, with police officials in Iran providing no further details due to the continuing investigations.
However, Al Shabab are often paid to secure the release of prisoners.
The men were kidnapped in international waters — possibly by pirates — before being handed over to the extremist group.
Piracy was once common in the Gulf of Aden but attacks have stopped almost entirely, an International Chamber of Shipping report said in August.
This is largely due to the work of an international naval coalition set up to stop piracy.
The former hostages were welcomed at Tehran's Imam Khomeini International Airport on Saturday night before being taken to their southern hometown of Chabahar, Iranian media reported.
Their release comes about a month after Somali police discovered 20 foreigners — 14 Iranians and six Pakistanis — near territory controlled by the militant group.
At the time, Somali police said some had been kidnapped by Al Shabab in 2014 while others had been abducted on the country's southern coast of Harardhere in mid-2019.
Al Shabab, which controls large parts of rural Somalia, has been trying to overthrow the central government for 15 years and has funding its insurgency through criminal activities such as kidnappings.
Somalia has also been plagued by piracy for years, although attacks on ships have declined sharply in recent years since they hit a peak of 176 in 2011.
In 2020, three Iranian fishermen believed to be the last hostages held by Somali pirates were freed after five years in captivity.
