LA MANOUBA, Tunisia: One of Tunisia's main mausoleums of the Sufi sect has been burned down in an overnight arson attack, an AFP journalist said Tuesday, amid a spate of attacks on Sufi shrines by increasingly assertive Salafists.

The Saida Manoubia shrine or zawiya in the western La Manouba suburb of the capital was attacked by five armed and hooded men who shinned down ropes from the mausoleum's roof, Melika, an employee, told AFP.

She said they had tyres and petrol with them and torched the mausoleum which was completely gutted. Armed with knives, they also robbed the four women employees present of their jewellery, Melika said.

Hundreds of people came to the site on Tuesday to survey the damage, among them the police chief and political officials.

However, the authorities have not yet said whether there will be an inquiry into the attack, the latest in a series of desecrations of Sufi shrines by radical Islamists.

At least another three Sufi shrines have been completely destroyed and several others have been forced to close, according to the ministry of religious affairs, which has acknowledged an upsurge in such attacks.

Since the early centuries of Islam, Sufi orders have always aroused suspicion among orthodox Muslims.

Members of Tunisia's militant Salafist movement, thought to number between 3,000 and 10,000, have been implicated in numerous acts of violence since last year's revolution.

On September 14, hundreds of radical Islamists angered by a US-made film mocking their religion attacked the US embassy in Tunis and a neighbouring American school in a day of violence that left four people dead and dozens wounded.

The Islamist-led coalition government has been strongly criticised for failing to clamp down on the extremists, who Tunisia's secular President Moncef Marzouki has warned pose a "great danger" to the region.