TUNIS, Tunisia (AP) — Authorities say at least 21 people are dead after an attack on a major museum in the Tunisian capital, and some of the gunmen may have escaped.

Tunisia’s prime minister, Habib Essid, told national television that 21 people were killed: 17 tourists, two gunmen, a Tunisian security officer and a Tunisian cleaning woman. He said the dead tourists came from Italy, Poland, Germany and Spain.

He said two of the attackers were killed in a gunfight with police, and that security forces are hunting for two or three others believed to have been involved.

It’s not clear who the attackers were but security forces immediately flooded the area. Tunisia’s parliament building, next to the museum, was evacuated.

The attack was the worst in years on a tourist site in Tunisia, which is struggling to solidify its young democracy and prevent violence by Islamic extremists.