One of the gunmen who killed tourists and others at a prominent Tunisian museum was known to the intelligence services but no formal links to a particular extremist group have been established, the prime minister said Thursday.

The attack Wednesday on Tunisia's National Bardo Museum left 23 dead, scores wounded and threatens both Tunisia's fledgling democracy and its struggling tourism industry. It was the worst attack at a tourist site in Tunisia in years.

Razor wire ringed the Bardo Museum on Thursday and security forces guarded major thoroughfares in Tunis, the capital, as authorities hunted for two or three more people believed to have been involved in the attack. Two of the gunmen were killed Wednesday by police.

The attack spells oceans of trouble for the tourism industry, which brings throngs of foreigners every year to Tunisia's Mediterranean beaches, desert oases and ancient Roman ruins _ and which had just started to recover after years of slump. Two major cruise ships whose passengers had been among the victims left the port of Tunis early Thursday.

A Spanish man and a pregnant Spanish woman who had been inside the museum during the attack hid in the building all night in fear and were retrieved safely Thursday morning by security forces, Tunisia's health minister told The Associated Press.

Health Minister Said Aidi said the death toll rose Thursday to 23 people, including 18 foreign tourists, with almost 50 people wounded. Five Tunisians were killed, including two attackers. Aidi said all the injuries came from bullet wounds, and that several victims were brought in without identity documents.

Moncef Hamdoun, an official with the Charles Nicolle hospital where many victims were taken, said seven of the dead remain unidentified.  He listed the others who were slain as: three Japanese women, a Spanish man and a Spanish woman, a Colombian woman, an Australian man, a British woman, a Belgian woman, a Frenchman and a Polish man.

Tunisian Prime Minister Habib Essid, in an interview with France's RTL radio, said Tunisia was working with other countries to learn more about the attackers, identified as Yassine Laabidi and Hatem Khachnaoui. They were killed by security services in a raid.

He said Laabidi had been flagged to intelligence, although not for "anything special.''

No one has claimed responsibility for the attack. Tunisia has faced scattered extremist violence, and a disproportionately large number of Tunisians have joined Islamic State fighters in Syria and Iraq.

Twitter accounts associated with the group praised the attack. Ifriqiyah Media, which has aired claims from Tunisian extremists in the past, posted what it said were details about the attack, according to the SITE Intelligence Group, which monitors extremist activity online. The post calls on Muslims to attack tourists, but does not say who orchestrated the attack.
Legislator Bochra Belhaj Hmida, of the secular majority party Nida Tunis, told the AP that about 2,000 suspected terrorists are believed to be in Tunisia, many of whom joined extremists in Iraq or Syria then returned home.

"They are in a situation of being lone wolves, where each of them is free to do the actions they want,'' she said. ``These are people who are let loose with weapons and wherever they can strike, they will not forgo the opportunity.''

Associated Press reporters Mari Yamaguchi in Tokyo, Jeff Schaeffer in Tunis, Monika Scislowska in Warsaw, and Lori Hinnant in Paris contributed to this report. (AP)