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