Iranian authorities have confirmed that six crew members from the seized container vessel Touska have been freed and returned home. Efforts are continuing to secure the release of the remaining personnel.
Citing the semi-official Tasnim News Agency, authorities said the vessel sailed under the Iranian flag. US forces intercepted it on 19 April near the port of Chabahar in the Gulf of Oman.
The United States has not publicly detailed the operation, but Tehran has strongly criticised the move.
Iran has described the detained crew as hostages and continues to demand their release.
Officials have condemned the seizure, calling it an unlawful act.
The country's military leadership, including the Khatam al-Anbiya Central Headquarters, said they did not take an immediate response at the time. They cited the presence of crew members' families on board as the reason.
State broadcaster Press TV earlier cited a senior security official. He warned that continued US actions at sea could provoke a strong military response.
Iranian sources have argued that there are limits to restraint. They suggested that further escalation may follow if the situation persists.
Tensions have also been raised at the diplomatic level. Iran's envoy to the United Nations, Amir Saeid Iravani, has formally complained about the incident, stating in a letter to the UN and the Security Council that such seizures amount to unlawful interference in international trade.
The developments come against the backdrop of increased friction in the Strait of Hormuz, where the United States has reportedly imposed restrictions affecting vessels linked to Iran. These measures followed unsuccessful negotiations between the two countries held in Islamabad on 11 and 12 April.
Those talks had taken place shortly after a ceasefire on 8 April involving Iran, the United States, and Israel, which brought an end to several weeks of conflict. The situation remains tense as diplomatic and military signals continue from both sides.