Tunisian prime minister Hamadi Jebali has condemned the killing of prominent opposition politician Chokri Belaid, saying it was a political assassination and a blow to the Arab Spring revolution.
"By killing him they wanted to silence his voice," added Jebali, who heads the government led by the moderate Islamist Ennahda party which won Tunisia's first post-Arab Spring election in 2011.
He said the identity of the killer was unknown.
More top news
Three people who had been arrested on suspicion of murder have been released without any further action.
The deadline of Zimbabwe's ruling party for Robert Mugabe to leave or face impeachment has passed.
The former WTA World No 1 doubles and No 2 singles champion died after a long battle with cancer.