Tunisia’s interior minister has said that government forces have killed an extremist leader and nearly wiped out his group, as European tourists continue to leave the country amid fears of new attacks.

Najem Gharsalli said late on Sunday night that recent security operations have targeted key members of the al-Qaida-linked Oqba Ibn Nafaa brigade. He said that one of the five people killed in an operation on Friday was the brigade leader, Mourad Gharsalli, accused of links to prominent warlords in Algeria and Mali. The minister called the operation a major security success.

Mourad Gharsalli Photograph: Ministère de l'Intérieur (Tunisie)

Tunisia, the only country to succeed in building a democracy after the Arab spring uprisings, is trying to defuse criticism from Britain and other countries that it has not done enough to protect tourists. An attack by an Islamic extremist in the resort of Sousse killed 38 people last month, and 20 were killed when gunmen stormed the Bardo museum in March.

The interior minister said the brigade was plotting attacks in Tunisia and sending Tunisians to fight jihad abroad. The brigade, based in the mountains near the Algerian border, is allied with al-Qaida’s north African branch.