According to an audio recording posted online, ISIS claimed responsibility for the attack and described the museum as a 'den of infidels and vice.'
"The attack was just the first drop of the rain," reports quoted the militant group. The militant group termed the attackers as 'knights' and warned of more such attacks.
US officials are investigating the authenticity of the audio but say that there is no reason to doubt the ISIS claim.
Meanwhile, Tunisian President Beji Caid Essebsi said that 'Tunisia was in war with terror.' "Savage minority groups would not frighten us," he said.
Two militants , dressed in military uniforms, jumped out from a vehicle and shot at tourists who were boarding a bus at the museum. The attackers then barged into the museum trying to take some hostages before being shot by security forces.