Kuwait's foreign ministry summoned the Iranian ambassador to demand the release of four Kuwaiti nationals detained in the western Ahvaz region of Iran, it said in a statement published by state news agency KUNA on Friday.
The ministry was coordinating with Iranian security authorities to press for visits to the men and to facilitate their release, the statement said. It did not elaborate on who the men were or why they were being held.
Kuwait joined other Gulf states in pulling its ambassador out from Tehran last year, rallying behind regional powerhouse Saudi Arabia after the kingdom's embassy in Tehran was torched by protesters.
However, unlike Saudi Arabia, it stopped short of severing ties altogether and continues to maintain an embassy in Tehran.
(Reporting by Ahmed Hagagy and Ahmed Tolba, Writing by Katie Paul; Editing by Mark Trevelyan)