Islamists tried Friday to set light to a street of brothels in Tunis but were dispersed by police using helicopters, a police official said.
"About an hour ago Islamist tried to get into Abdallah Guech Street to set it on fire," the official said. "Residents kept them out until the security forces arrived."
The street near the Medina contains one of Tunis's main brothels, well known to foreigners as well as locals.
"Police blocked off the street and succeeded in dispersing the demonstrators," the official said.
Dozens of Islamists calling for Tunisia's brothels to be closed had rallied outside the interior ministry following Friday prayers before marching to Abdallah Guech Street.
"No to prostitution houses in a Muslim country!" they shouted.
Some brandished posters claiming "Closing houses of prostitution is an obligation."
"We cannot accept that women are treated like goods. We demand the closure of all kinds of prostitution houses in Tunisia," 20-year-old protester Anas told AFP, claiming the rally had been organized "spontaneously".
"Arab tourists come to Tunisia especially to visit these brothels," said Anas, adding that such establishments had already been closed in other parts of the country.
"It's a shame for all Arab Muslim countries to allow these houses to remain open," said 24-year-old student Mounir.
The protesters included women, some wearing veils -- a rarity in Tunisia -- while others sported tight jeans.
As well as the Medina area other prostitutes ply their services at Tunis cafes, charging fees that never go beyond 20 dinars (10 euros, $14).
The protest came as Tunisia remains volatile following the mass protests that ousted president Zine El Abidine Ben Ali a month ago.