Six people believed to have orchestrated the killing of an opposition figure whose assassination in February plunged Tunisia into a major political crisis have been identified, a minister said Wednesday.

"We have identified the sponsors and the authors of the assassination of Chokri Belaid," said Noureddin B'Hiri, senior adviser to the prime minister, after a cabinet meeting.

B'Hiri said the details would be revealed "soon" by Interior Minister Lotfi Ben Jeddou, without saying when.

Belaid was gunned down outside his home on 6 February, in a brazen attack that shocked Tunisians and sparked a political crisis that brought down the government of Islamist premier Hamadi Jebali.

The interior ministry blamed the killing of Belaid, who was an outspoken critic of Jebali's ruling Ennahda party, on a cell of radical Islamists.

In April, the government released the photos and names of five Islamists allegedly implicated in the attack, including the alleged gunman, and appealed for help in arresting them.

Since the revolution that toppled the regime of Zine El Abidine Ben Ali in January 2011, hardline Islamists have been blamed for numerous acts of violence, notably an attack on the US embassy last September that left four assailants dead and the killing of Belaid.