Tunisian police have killed seven fighters, including a senior commander wanted for the assassination of two opposition leaders, in a daylong standoff in Tunis, the interior ministry has said.
The raid was one of the deadliest since Tunisian forces cracked down on Ansar al-Sharia, whose leader declares allegiance to al-Qaeda, and which the US lists as a foreign terrorist group.
Among those killed was Kamel Ghadghadi, a senior member of Ansar al-Sharia, wanted for killing seven soldiers, and a suspect in assassinating opposition leaders Chokri Belaid and Mohamed Brahmi.
One National Guard member also died in the clash, as hundreds of anti-terrorism units flooded the neighbourhood.
"Ghadghadi is among those killed. This is the best present for Tunisians a year after the murder of Belaid," Interior Minister Lofti Ben Jeddou told reporters at a news conference on Tuesday.
Belaid was shot dead outside his home on February 6 last year, in a brazen attack that led to a political crisis which brought down the government of Prime Minister Hamadi Jebali.
Brahmi, who was a member of the People Movement Party, part of the same coalition as Belaid, was shot dead in front of his house in the capital in July.
Officials showed reporters a photograph of what they said was Ghadghadi's corpse, wearing a suicide bomb belt. Other explosive material and weapons were also found in the house.
Ansar al-Sharia was one of the armed groups to emerge after Tunisia's 2011 popular uprising ousted President Zine El-Abidine Ben Ali, whose regime suppressed and jailed Islamist leaders.
Rise of the Salafists
The rise of conservative Salafi movements, who promote the establishment of an Islamic state, has alarmed many in Tunisia, which for decades was considered one of the most secular countries in the Arab world.
The struggle over the role of religion in government and society has emerged as the most divisive issue in Tunisia.
Ennahdha, a moderate Islamic group, won Tunisia's first elections since the revolt but formed a coalition with two non-religious parties.
But the Salafists want a broader role for Islam, alarming secular elites who fear they will seek to undermine Tunisia's nascent democracy.
Ansar al-Sharia was blamed for storming the US embassy in Tunis in late 2012. The moderate Islamist government at the time declared Ansar al-Sharia a terrorist organisation after accusing the group of murdering the opposition leaders.
Three years after its Arab Spring uprising, Tunisia is led by a caretaker government that took over after Ennahda stepped down in a compromise to end a crisis sparked in part by the killing of Belaid and Brahmi.
Tunisia formally celebrates a new constitution on Friday, with French President Francois Hollande and other dignitaries invited to the ceremony to mark the North African country's progress to democracy.