Tunisia's interior minister said on Friday that secular opposition politician Mohamed Brahmi had been killed with the same gun that was used to kill his party leader Chokri Belaid six months ago, suggesting the involvement of the same hardline Salafist Islamist group.

Lotfi Ben Jeddou told a news conference: "The same 9mm automatic weapon that killed Belaid also killed Brahmi."

He named the main suspect as hardline Salafist Boubacar Hakim, already being sought on suspicion of smuggling weapons from Libya.