Kalashnikov-armed gunmen wearing military uniforms attacked the National Bardo Museum in downtown Tunis on Wednesday, killing several Tunis nationals as well as foreign tourists, and taking several others hostage.
Two gunmen and a security officer were among the dead after a successful raid by security forces ended the standoff.
Tunisian Prime Minister Habib Essid said that 19 people were killed, including 17 tourists, according to The Associated Press. The tourists were from Italy, Germany, Poland and Spain.
Including the gunmen and a museum security officer, who was injured in an exchange of fire and later succumbed to his injuries, the death toll is 21.
The tourists were attacked while they were getting off a bus to enter the museum, Essid said, noting this is the first attack there targeting tourists.
The attackers' identity and associations were not immediately known.
22 tourists were injured and another two Tunisian men, Essid said.
Tunisia's health minister Said Aidi stated some of the injured were from France, South Africa, Poland, Italy and Japan, AFP reported.
Essid indicated a manhunt was underway for more suspects who may have been involved in the attack.
Tunisian state media outlets said that the gunmen initially held ten hostages in a siege that lasted near two hours.
The National Bardo Museum is the country's largest, built within a 15th-century palace. The museum houses one of the world's largest collections of Roman mosaics. It is located near and shares grounds with the Tunisian Parliament building, which was evacuated at the sound of gunfire.
The Arab Spring began in Tunisia in 2010, and the attack is a blow to the newly-formed North African democracy bordered by Libya and Algeria.
The country has been grappling with Islamic extremist violence, some linked to al-Qaida and some to ISIS. ISIS' ranks have been joined by a disproportionately large number of Tunisians (3,000) in Syria and Iraq, according to the AP.
