A Vietnamese oil tanker earlier seized by Iran was free in open water Wednesday, ending the latest maritime confrontation involving Tehran amid stalled negotiations over its tattered nuclear deal with world powers.

Axar.az reports the Sothys left a position off Iran’s Bandar Abbas port and had reached international waters in the nearby Gulf of Oman early Wednesday. The vessel appeared anchored there, but there was no information about its crew.

Shahrokh Nazemi, a spokesperson for Iran’s mission to the United Nations, told the AP on Wednesday that “Sothys left Iranian waters last night after transferring the oil.”

Vietnamese officials could not be reached for comment, though its officials earlier acknowledged trying to obtain more information about the seizure from Iran.