Iran on Wednesday summoned the British ambassador, the foreign ministry said, after he called in an online post on Tehran to release detainees including journalists.
On Tuesday, ambassador Simon Shercliff paid tribute "to all journalists prevented from doing their jobs and facing threats to their safety" on the occasion of National Journalists' Day in Iran.
"We reiterate our call for Iran to release all arbitrarily detained individuals, including all journalists," he said on Twitter, which has recently been rebranded as X.
Iran's foreign ministry said it summoned the British ambassador to protest what it described as "interventionist content".
The ministry said it also conveyed Iran's "strong protest" against his stances which were "unmeasured... irresponsible" and contrary to "diplomatic norms and regulations".
On Tuesday, the reformist Shargh daily reported that over 90 journalists have either been arrested or questioned in Iran since nationwide protests rocked the Islamic republic last year.
Most have been released on bail or granted amnesty, but the fate of 11 journalists, including six detained and five others awaiting verdicts, "is still unknown", said the report.
Mass demonstrations erupted in September 2022 following the death in custody of 22-year-old Iranian-Kurd Mahsa Amini, who was arrested for allegedly breaching the Islamic republic's strict dress code for women.
Hundreds of people including security forces were killed and thousands arrested over their participation in what the authorities have described as "riots" fomented by the West
Among the detained journalists are Niloufar Hamedi and Elaheh Mohammadi, who covered Amini's death and have been in custody since September.
The pair are being tried separately behind closed doors in Tehran and were charged in November with propaganda against the state and conspiring against national security.