This undated file photo shows members of al-Qaeda affiliate Ansar al-Sharia in Tunis (Photo:Reuters)
Tunisian police killed an Islamist militant in a gunbattle in Tunis and captured three people, including one suspected of involvement in the assassination of an opposition leader last year, authorities said.
Hmed Malki, captured late on Saturday, is a main suspect in the killing of Mohamed Brahmi, whose death helped tip Tunisia into a political crisis, an Interior Ministry spokesman said.
It was the second major operation in Tunisia in a week after seven militants armed with suicide bomb vests and explosives were killed in a raid on a house north of the capital last week. A police officer was also killed.
Officials did not name the group involved, but Tunisian forces have cracked down on Ansar al-Sharia, which emerged after Tunisia's 2011 uprising that ousted Zine El-Abidine Ben Ali, who suppressed and jailed Islamist leaders.
Ansar al-Sharia was blamed for storming the US embassy in Tunis in 2012 and has since been listed by Washington as a terrorist organisation, with ties to al Qaeda in the Islamic Maghreb.
The threat of Islamist militancy is one of the main challenges for the caretaker government that is in place until elections later this year, under an agreement to see Tunisia complete its transition to full democracy.
After the killing of Brahmi and another opposition leader, the ruling Islamist party Ennaha faced protests and pressure to resign and eventually agreed to step down for the technocrat government to take over.