Tunisian Prime Minister Habib Essid fired half a dozen police officials after an attack on a national museum last week claimed several lives, the government said Monday. The six police chiefs were in charge of various duties, including tourist security in the area that houses the museum and the country's parliament, and an intelligence group.

"He visited [the area around the museum] last night and saw several deficiencies," Essid's communications director, Mofdi Mssedi, told Agence France-Presse. "So he has decided to fire a number of officials, including the Tunis police chief and the police chief for the Bardo [area]."

On Sunday, President Beji Caid Essebsi announced that authorities were looking for a third attacker in the shooting at the North African cultural center, which left 23, including 19 foreign nationals, dead last week. Two attackers were also killed during the incident. Security officials who were on duty at the museum were reportedly on a coffee break when the attack began.

Tunisia has enjoyed relative prosperity since the 2011 uprisings that overthrew former President Zine El Abidine Ben Ali. The country held its first democratic elections and saw a peaceful transfer of power in December. However, the country’s security forces have grappled with a growing threat from Islamic extremists in the country’s remote mountain regions, and an inflow of rebel fighters from neighboring Libya. Tunisia has also emerged as one of the biggest sources of foreign fighters who travel to join the Islamic State group.

Over 400 suspects have reportedly been detained by security forces across the country since last week's attack, and 20 were arrested in a raid on four terror cells involved in sending militants to Libya, security forces said last Monday. A Tunisian interior ministry spokesman told reporters on Saturday that 10 of the apprehended militants were believed to be directly involved with the attack, and added that “there is a large-scale campaign against the extremists,” Reuters reported.