Hardline Islamists have prevented an Iranian group from performing at a Sufi festival in Kairouan, south of Tunis, deeming their Shiite chanting violated sacred values, Tunisian media reported on Thursday.
It was the second time in two days that radical Muslims have disrupted cultural performances in Tunisia.
"When an Iranian group were due to appear on stage, they were blocked by a group of protesters apparently belonging to the Salafist movement," private radio station Shems FM said, quoting a journalist at the festival.
"One of the protesters explained that a petition circulating on the Internet for several days, asked the Iranian singers not to perform, because to do so amounted to an attack on the sacred from a Sunni point of view," it added.
Culture ministry spokesman Samir Messaoudi confirmed to AFP that a group of Salafists prevented the Iranian group from performing at the Sufi chanting festival in Kairouan, 160 kilometres (100 miles) from the capital.
But he said the authorities had intervened and sent the protesters away.
The group then refused to appear, "saying that they were not psychologically ready to sing," Messaoudi added.
Wednesday's protest followed a similar confrontation on Tuesday in a town north of the capital, where Salafists blocked a stand-up show by a well-known Tunisian comedian who they accused of offending Islam.
Tunisia's hardline Islamists have grown more confident since the mass uprising that toppled former dictator Zine El Abidine Ben Ali last year.
In mid-June, suspected Salafists sneaked into a gallery in Tunis and destroyed some works of art they considered offensive to Islam, triggering riots that left one person dead and more than 100 injured.
Ennahda, the moderate Islamist party that heads Tunisia's ruling coalition, has struggled to clarify its line on the Salafists, with recent violence sparking criticism that it has done too little to stop them.
NGOs have criticised a bill that Ennahda filed in parliament earlier this month that could see anyone convicted of violating sacred values jailed for up to two years.
Two young Tunisians were given prison sentences in June on charges of disturbing public order and attacking morals, after posting caricatures of the Prophet Mohammed on Facebook.