Tunisia has arrested the owner of a private TV station and his son for treason for inciting violence and working for ousted leader Zine al-Abidine Ben Ali's return, the state news agency said on Sunday.

The owner of Hannibal TV (Larbi Nasra), who is a relative of the former president's wife, is using the channel to abort the youth's revolution, spread confusion, incite strife and broadcast false information, a statement citing an authorised source said.

The aim is to create a constitutional vacuum, ruin stability and take the country into a vortex of violence that will bring back the dictatorship of the former president.

Veteran strongman Zine al-Abidine Ben Ali was overthrown this month in a popular uprising over poverty, corruption and political repression that stunned Arab and Western governments who had long backed Ben Ali as a bulwark against Islamists.

But since then, Tunis and other cities have seen daily protests against an interim government containing many loyalists from Ben Ali's era, including prime minister Mohamed Ghannouchi, as well as some opposition politicians.

Former members of Ben Ali's RCD ruling party retain key ministries, notably interior, defence and foreign affairs.

Saleh Attia, a columnist from the daily Assabah newspaper, voiced surprise over Nasra's arrest, saying he was not viewed as a regime insider and it was a sign the protests had begun to unnerve the authorities, which were divided over how to proceed.

This is to stop the street that wants the government to fall. They are frightened of these protests which have spread to other provinces and now have reached the prime minister's office, he said.

STATION BACK ON AIR

The protests, which have not let up, have so far been peaceful with police on Saturday and Sunday allowing protesters to break through barricades placed at the prime minister's compound.

The army led the way in an effort to restore order after Ben Ali fled to Saudi Arabia, winning praise on Tunisian state television. The authorities said Ben Ali had left behind militias that clashed with the army, which has imposed an ongoing night curfew.

The Tunisian news agency said Nasra and his son had been arrested to secure the nation's safety and the revolution's success.

They will be transferred to the justice system for prosecution over high treason and conspiracy against the country, the agency said.

Lutfi Salami, spokesman for the channel set up in 2005, declined to comment on the charges but said the state broadcasting authorities had stopped the station's broadcast.

The station was back on the air within hours, however. Tunisian state TV said opposition cabinet minister Nejib Chebbi had intervened to ensure that Hannibal TV resumed broadcasting, and apologised on behalf of the government for the disruption.

Like Tunisian state television, Hannibal has carried discussion shows about the uprising, ongoing demonstrations and future of the transitional government.

Ghannouchi defended himself against criticisms in an interview on state TV on Friday.

There is a struggle between security, military and political circles and I also suspect there is international pressure to stop things getting out of hand, Attia said.

Although Nasra was a relative of Leila Trabelsi, Ben Ali's wife, he was not considered a regime insider, he added. Why do they suddenly say this now? he said.

Sihem Bensedrine, a rights activist harassed by Ben Ali's regime, said the move against the station was worrying.

This is against freedom of expression. I fear now that the remains of the former regime have started a move against this revolution, she said.