Tunisia’s Bardo Museum is due to reopen less than a week after gunmen killed at least 22 people, mostly European tourists, in the capital Tunis.
A concert and a public rally are expected, with museum officials saying they want to show the world that the gunmen “haven’t achieved their goal”.
There are fears the attack – claimed by Islamic State (IS) – will hit Tunisia’s vital tourism industry.
On Monday, Tunisia’s prime minister dismissed six police chiefs.
Habib Essid’s office said he had noted several security deficiencies during a visit to the museum, which houses a major collection of Roman mosaics and other antiquities.
Two of the gunmen were killed by the security forces during last Wednesday’s attack, while a third is on the run, officials said.
The attack was the deadliest in Tunisia since the uprising which led to the overthrow of long-serving ruler Zine al-Abidine Ben Ali in 2011.
Suspects have been arrested over the attack but just two gunmen were thought to have raided the museum.
They are said to have been trained in Libya in an area controlled by Islamic State (IS) militants.
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The two gunmen seen in footage released by the interior ministry were named as Yassine Laabidi and Hatem Khachnaoui.
They were both killed in a gunfight with security forces inside the building.
In an interview with Paris Match, Mr Essebsi said that “shortcomings” in Tunisia’s security system meant “the police and intelligence services had not been thorough enough in protecting the museum”.
However, he added that the security services “reacted very efficiently” to the attack and had helped save dozens of lives.
At least 20 foreigners were among those killed in the attack, including British, Japanese, French, Italian and Colombian tourists.
Following the attack, large numbers of Tunisians gathered outside the museum to protest against terrorism.
Tunisia has seen an upsurge in Islamist extremism since the 2011 revolution – the event that sparked the Arab Spring.
The leader of Tunisia’s moderate Islamist party, Ennadha, says the country will continue to be under threat of attack as long as neighbouring Libya remains unstable.
Rached Ghannouchi told the BBC that IS would not be able to establish a foothold in Tunisia itself but young men were being armed in Libya and crossing borders that were hard to control.
In recent years Tunisia has been the largest exporter of jihadists in the region, and many of them end up fighting in Syria, reports the BBC’s Rana Jawad in Tunis.