Tunisian opposition member Mohamed al-Brahimi was killed with the same gun used to assassinate politician Chokri Belaid six months earlier, Interior Minister Lutfi bin Jidu said Friday.
“The same 9mm automatic weapon that killed Belaid also killed Brahimi,” bin Jidu said.
While four suspects have been arrested, there were around 14 involved in the killing of Brahimi and Belaid, the minister added.
The main suspect is hard-line Salafist  Abu Bakir Hakim, who is already being sought on suspicion of smuggling weapons from Libya, bin Jidu said.
“I want to emphasize that crimes of political assassinations are usually done with top secrecy... but we were capable of finding suspects with evidence,” he said.
Most of the suspects were believed to be members of the local hardline Islamist group Ansar al-Sharia.
Since the ouster of secular dictator Zine al-Abidine Ben Ali in 2011, Ansar al-Sharia, considered to be the most radical Islamist group, emerged in Tunisia.
While the government is led by a moderate Islamist party, Ennahda, Salafists covet a broader role for religion in the country.
Brahimi, a father of five, was shot 12 times outside his home, medical sources said Thursday. However, bin Jidu said he was shot 14 times.
Brahimi was general coordinator of the Popular Movement, and a member of the National Constituent Assembly.
Belaid was an opposition leader with the leftist, secular Democratic Patriots’ Movement.