Tunisia wants to have ousted president Zine al-Abidine Ben Ali and his family arrested and put on trial for theft and currency offences, the justice minister said on Wednesday.

The international police organisation Interpol has been asked to help arrest Ben Ali, his wife Leila Trabelsi and other family members who have fled the country, Lazhar Karoui Chebbi told a news conference.

Ben Ali went to Saudi Arabia this month after weeks of violent protests against poverty, repression and corruption. He amassed vast riches during his 23 years in power, with his family controlling many of Tunisia's biggest companies.

'We are asking Interpol to find all those who fled, including the president and this woman, for trial in Tunisia,' the justice minister said.

Chebbi also said six members of the presidential guard would be put on trial for inciting violence after Ben Ali's departure.

Meanwhile, demonstrators demanding a purge of former regime loyalists in an interim government clashed with Tunisian police on Wednesday.

Clashes broke out near government offices in the old city, or casbah, of Tunis, where riot police fired teargas at hundreds of demonstrators, mainly teenagers and young men who threw stones.

The interim government will be reshuffled on Wednesday, ministers said. It has struggled to assert itself in the face of protesters' demands to sack the remaining allies of president Zine al-Abidine Ben Ali, who fled the country on Jan. 14.

 Wednesday's protesters appeared to be Tunisians from the rural regions of the Mediterranean country's deprived hinterland who have been camping out at the government compound. .-Reuters