Tunisian opposition politician Mohamed Brahmi has been shot dead outside his home in the capital, Tunis, officials say.
Mr Brahmi, 58, led the nationalist Movement of the People party.
It is the second time an opposition party leader has been killed this year.
Protesters have gathered in Tunis and in Mr Brahmi’s hometown, Sidi Bouzid, calling for the government to resign. Tunisia largest labour union has announced a general strike for Friday.
In February, prominent secular politician Chokri Belaid was also shot outside his house in Tunis.
His murder sparked nationwide mass protests and forced Prime Minister Hamadi Jebali to resign.
Police inspect Mohamed Brahmi’s car (25 July 2013) The opposition leader was gunned down in his car outside his home in Tunis
Gunmen on a motorbike shot Mr Brahmi in his car in front of his wife and daughter on Thursday morning, Movement of the People party officials said.
Local media reported the assailants fired 11 bullets at the politician. It is not known yet who was behind the attack.
The family of Mr Brahmi has accused the governing Islamist Ennahda party of being behind the killing.
The party has not responded to the claim, but released a statement expressing “sadness and shock” at the “cowardly and despicable crime”.
Mr Brahmi’s wife, Mbarka, and her daughter Belkis were joined by angry Tunisians outside the hospital in Tunis where the politician died.
Large crowds also gathered in front of the Ministry of Interior in the capital in protest at the killing.
Protesters outside the Interior Ministry in Tunis (25 July 2013) Large crowds also gathered outside the Ministry of Interior in Tunis in protest at the killing
“People have blocked roads and set tires alight,” a local resident told the Reuters news agency.
M.D