DUBAI, United Arab Emirates — An advocacy group for journalists is asking Oman to release a state radio reporter detained in the country since late April.

Reporters Without Borders on Friday called for the release of Sulaiman al-Moamari, who heads cultural coverage for Oman’s national radio broadcaster.

The group says al-Moamari reportedly is being held in solitary confinement by Oman’s domestic intelligence agency, the Internal Security Service. The group asked Oman to give its reason for detaining al-Moamari, as well as grant him a fair trial or release him immediately.

Omani officials could not be reached for comment Friday, the start of the country’s weekend. The state-run Oman News Agency has not reported on al-Moamari’s detention.

Oman, ruled by Sultan Qaboos bin Said, has not seen major unrest following the Arab Spring-inspired protests in 2011.