Tunisia, the birthplace of the Arab Spring, faces the prospect of fresh political turmoil after an opposition leader was shot dead outside his home, in the country's second political assassination this year.
Mohammed Brahmi (58), the leader of the Left-wing nationalist Movement of the People party, was killed after being hit by 11 bullets fired by two gunmen as he sat in a car in the capital, Tunis.
The attackers sped off on a moped after the incident, which was witnessed by Mr Brahmi's wife and daughter.
Another Left-wing politician, Chokri Belaid, who belonged to the same Popular Front coalition as Mr Brahmi, was killed in a similar incident in February in an assassination that the government blamed on Islamic extremists.
The latest murder, coinciding with the 56th anniversary of Tunisia's independence, threatened to plunge the North African country deeper into instability as Mr Brahmi's supporters gathered in Tunis and other cities.
Large crowds congregated outside the interior ministry in the capital, while there were reports of demonstrators blocking roads and setting light to tyres in Mr Brahmi's home town of Sidi Bouzid, the site of the initial protests that set in motion the Arab Spring.
The country's constituent assembly, of which Mr Brahmi was a member, declared yesterday a day of mourning.
The killing was condemned by Francois Hollande, the French president, who urged "all political and social forces in Tunisia to demonstrate the spirit of responsibility needed to preserve national unity and to guarantee the continuation of the democratic transition".
France is the former colonial power in Tunisia, whose government is led by the moderate Islamist Ennahda party and supported by two smaller secular parties. Ennahda has been criticised by the opposition for failing to curtail Islamic extremists, and even for encouraging their activities.
The party has denied the accusations. It issued a statement calling Mr Brahmi's murder a "cowardly and despicable crime" and demanding the arrests of those responsible.
Tunisia has struggled with democratic transition since former dictator Zine el Abidine Ben Ali was driven from power in the first of the Arab Spring uprisings in January 2011. (© Daily Telegraph, London)