The decision to reopen Tunisia’s National Bardo Museum to the public after last week’s deadly terrorist attack has been be postponed.

The Associated Press noted that the museum’s curator Moncef Ben Moussa said Tuesday that the plans to reopen the museum would be delayed until Sunday due to security and organizational issues. However, he said that there would be a special ceremony held Tuesday evening for select guests.

As previously reported, the famed Bardo Museum is the site of last week’s attack in which gunmen dressed in military fatigues opened fire on those inside. A total of 21 people were killed.

A website linked to ISIS claimed that the terror organization was responsible for the attack.

Tunisian authorities have arrested several people who they believe were involved, but are still searching for the mastermind. The gunmen who entered the museum were fatally shot by police.

After the deadly attack in the country Prime Minister Habib Essid urged all Tunisians to unite during the tragic time.