Tunisia's main labour union urged the government Thursday to begin talks immediately to defuse a ticking social bomb that threatens to derail the country's nascent democratic process.

"It is in the interest of the government to rapidly launch negotiations with the main union because the social situation is explosive," said Abid Briki, who heads the General Union of Tunisian Workers (UGTT).

Interim president Foued Mebazaa had said Wednesday he would shortly hold talks with UGTT, a key player in the popular revolt that led to the led to the downfall of the strongman Zine El Abidine Ali , but had not specify a date.

Briki spoke as a woman was in critical condition Thursday after she set herself on fire after being unable to obtain medication for her cancer-stricken husband.

The attempted public suicide was reminiscent of last December's self-immolation by a desperate young street vendor whose death triggered the nation-wide revolt and inspired a similar uprising in Egypt.

His death came to symbolise the grievances of many in Tunisia and the rest of the Arab world against a corrupt leadership that failed to address poverty, rampant unemployment, surging costs and housing problems.

Briki meanwhile urged called on the government to act immediately on the issue of permanent jobs for temporary workers and on seriously considering a long-standing union request to create an unemployment fund.

Public anxiety has simmered despite Ben Ali's ouster on January 14 following the mass protests that were partly stoked by frustrations over poverty and unemployment. While the jobless rate is officially 14 per cent, the percentage of graduates out of work is double that.

Organised and spontaneous strikes have slowed down the economy and the new government's pledge to cut ties with the former regime has done little to appease resentment among the country's poorest.

Mebaaza urged Tunisians to show "patience" as the Senate this week unanimously agreed to grant him wide power to restore order.

"Your demands are legitimate, but you must understand the difficult situation in which our country is confronted," he said Wednesday.

On the security front, a 26-year-old man was wounded by a stray bullet as a soldier fired warning shots to disperse a crowd of jobless people who had massed outside the social affairs ministry.

Lootings have been reported in the past few days in the northwestern city of Jendouba and in neighboring Kef, the official TAP news agency reported.

And police, closely associated with the hated Ben Ali regime, have played virtually no role in restoring law and order and have been accused by some of inciting unrest.

The trade union also needs to tackle discontent over the presence of members of Ben Ali's former ruling party in various industrial sectors and companies, Briki said.

While UGTT played a key role in holding rallies across the country, its leadership has recently been challenged by a leftist movement that accuses it of "collaborating" with the government and of corruption.