The Isil terrorist group has issued a statement claiming responsibility for the deadly attack on Tunisia's National Bardo museum, which killed 23 people.
The statement described the attack as a "blessed invasion of one of the dens of infidels and vice in Muslim Tunisia", and appeared on a forum that carries messages from the group.
The US-based SITE Intelligence Group also announced that Isil had claimed responsibility for the attack. The statement said there were two attackers and they were not killed until they ran out of ammunition.
And further attacks were promised in the statement.
"Wait for the glad tidings of what will harm you, impure ones, for what you have seen today is the first drop of the rain," it said.
Isil, which is based in Syria and Iraq, has affiliates in neighbouring Libya, where many Tunisians have gone to fight and train with extremist groups.
Earlier this week, a prominent Tunisian field commander for Isil was killed in fighting inside Libya. Tunisia's government, meanwhile, announced the arrest of nine people - four of whom were connected directly to the attack and five others who supported them elsewhere in the country, authorities said.
The attack on the museum, which houses Roman artefacts in Tunis, was the worst at a tourist site in Tunisia in years. The deaths of so many tourists prompted a leading Italian cruise ship line to announce it was cancelling all stops at Tunisia indefinitely. One of the gunmen was known to intelligence services, Prime Minister Habib Essid said. He told France's RTL radio that Tunisia was working with other countries to learn more about the dead attackers, identified as Yassine Laabidi and Hatem Khachnaoui.
He said Laabidi had been flagged to intelligence, although not for "anything special". It alleged that four of the nine held were directly linked to the attack and five had "ties to the cell". The army will also be deployed to major cities, the president added. Isil claimed that the attack was carried out by "two knights of the caliphate" and named them as Abu-Zakariya al-Tunisi and Abu-Anas al-Tunisi.
The attackers, who wore military-style uniforms and wielded assault rifles, burst from a vehicle and began gunning down tourists climbing out of buses. The attackers then charged inside to take hostages before being killed in a fire-fight with security forces.