Riot police gear up near protesters during a demonstration in Tunis February 6, 2013 (Reuters)

Protesters gesture to the police during a demonstration in Tunis February 6, 2013 (Reuters)

A man crosses the street as Tunisians demonstrate after the killing of Chokri Belaid in Tunis (AP)

Protesters remove barriers to demonstrate after the killing of opposition leader Chokri Belaid (AP)

A riot police officer salutes the ambulance carrying the body of Chokri Belaid (AP)

A demonstrator faces riot police officers after the killing of Chokri Belaid in Tunis (AP)

Tunisian protesters clash with riot police slogans (Reuters)

The body of Tunisian opposition leader Chokri Belaid is carried in an ambulance (Reuters)

Protesters plead with a plainclothes policeman (front) (Reuters)

Tunisians accompany the ambulance carrying the body of opposition leader Chokri Belaid (AP)