JEFFREY BROWN: And now to today's killing of a political leader in Tunisia, the birthplace of the Arab spring.
Margaret Warner reports.
MARGARET WARNER: Protesters poured into the streets of Tunisia's capital, Tunis, and other cities today in a fury over the assassination of Chokri Belaid. He'd been a leader of the opposition to the Islamist-led coalition government.
Belaid was gunned down this morning as he left his house in Tunis, and taken to a nearby medical clinic, where he was declared dead. Within hours, thousands of people massed near the Interior Ministry and elsewhere, with police firing tear gas, as the protesters fought back with stones. Belaid's brother joined in, charging the ruling Ennahda party was either behind the killing or did nothing to prevent it.
ABDELMAJID BELAID, Brother of Chokri Belaid: The message is, you shut up, or we kill you. The Ennahda party wants to rule the country on its own. Actually, he has been receiving threats of murder for a long time.
MARGARET WARNER: Officials of Ennahda denied any role, and, in France, Tunisia's moderate Islamist president, Moncef Marzouki, condemned the Belaid killing.
PRESIDENT MONCEF MARZOUKI, Tunisia: This assassination took place today itself, with the knowledge that I was to speak to you. This is a threat. It is a letter that has been sent, but which will not be received. We refuse this letter. We refuse this message and we will continue to unmask the enemies of the revolution and to continue our policies.
MARGARET WARNER: In late 2010, Tunisia saw the first mass protests of the Arab spring, and in January 2011 became the first to oust its longtime dictator.
The Islamist party Ennahda won parliamentary elections that October, but fell short of a majority and vowed to be inclusive in governing. But there've been growing tensions since then, including violent protests at the U.S. Embassy in Tunis last September.
Ultra-conservative Salafi Muslims, who are advocating a more Islamic identity for Tunisia, have been blamed for that attack and others. The Salafi influence has, in turn, alarmed the opposition. After today's assassination, Belaid's Popular Front party and its allies announced they will pull out of a constitutional assembly responsible for writing a new governing charter.
Tunisia's prime minister then announced he's dissolving the government and will form an interim government of technocrats, leading to new elections.