Organizers said dozens of people, led by a handful of maroon-robed monks, marched in Yangon to shut down a service marking the birthday anniversary of the Prophet Muhammad (peace be upon him).
Witnesses said the monks barged into the ceremony shortly after it started, demanding it be shut down.
Kyaw Nyein, the secretary of the Ulama Islam organization, described the latest assault on the Muslim gathering as a violation of religious freedom.
"We have celebrated this festival for my whole life. Now this seems like an attack on freedom of religion," Nyein said, adding, "The monks tried to stop the ceremony without saying what we had done wrong... Why aren't authorities taking action?"
Security forces did not intervene to stop the extremists.
In recent years, Buddhist hardliners have sought to restrict Muslim worship, destroying mosques and attempting to ban ceremonies such as the ritual slaughter of cattle during the festival of Eid al-Adha.
Rakhine has been under a military siege since October, forcing tens of thousands of members of the Rohingya to flee to neighboring regions in Kachin state or across the border to Bangladesh.
The military crackdown in Rakhine began after a deadly raid on a police post that the government said was carried out by the Rohingya.
There have been numerous eyewitness accounts of summary executions, rapes, and arson attacks against the Muslims since the crackdown began. The military has blocked access to Rakhine and banned journalists and aid workers from entering the zone.
International organizations and human rights groups have blamed Myanmar's security forces for abuses against the Muslim minority in Rakhine, including rape, killings, and the burning of more than 1,000 homes.