Tunisia's prime minister has promised to leave politics after elections being planned in the wake of President Zine al-Abedine Ben Ali's fall last week. In a TV interview, long-serving PM Mohamed Ghannouchi said he would quit "in the shortest possible timeframe". His transition government has promised to hold polls within six months, but it has so far not set a date. Mr Ben Ali fled to Saudi Arabia on 14 January. Protesters say all figures linked to his regime should quit. Mr Ghannouchi was a key ally of the ousted president, and has been struggling to restore calm under the new national unity government. In his TV interview late on Friday, he said he would retire from public life after the elections, and promised that all "anti-democratic laws" would be repealed by the transition cabinet. He added that under Mr Ben Ali, he had been "afraid, like all Tunisians". At least 78 people have been killed since a wave of protests began last December. Three days of mourning began on Friday. Flags were lowered, and at the Quds mosque in Tunis, an imam prayed for the dead and for democracy, the Reuters news agency reported. At Friday prayers, there was none of the heavy security around mosques seen under Mr Ben Ali's rule, nor the customary mentions of the former president by imams. 'National salvation' Mr Ghannouchi has left Mr Ben Ali's RCD party and said his interim government needs "clean hands" - but he has also said the transition to democracy needs experienced politicians. Meanwhile the country's main trade union, the General Tunisian Workers' Union (UGTT), has called for a new administration with no links with the ousted regime. The UGTT's deputy head, Abid Briki, told the AFP news agency that such a "national salvation government" was "in accordance with the demands of the street and political parties". The government has faced continuing protests against figures from the previous regime remaining in positions of power. Four opposition ministers quit over the issue, just one day after the cabinet was formed. The interim cabinet has promised to release all political prisoners and said previously banned political groups will now be legal. It has also announced that 33 members of Mr Ben Ali's family have been arrested. According to Interior Minister Ahmed Friia, one of those was Imed Trabelsi, a nephew of Mr Ben Ali's wife, who was previously reported to have been stabbed to death. Mr Ghannouchi also said on Friday that Tunisia would pay compensation to victims of abuse during Mr Ben Ali's rule, Reuters reported. Mr Ben Ali fled to Saudi Arabia following a wave of demonstrations attributed to economic grievances and resentment about a lack of political freedom. Mr Ben Ali's family was widely despised because of its conspicuous consumption and perceived corruption. The protests against his rule began after a man set himself on fire in central Tunisia on 17 December. Source: BBC