TUNIS (AFP) - Tunisia said Thursday it would deploy soldiers to beef up security in major cities after an attack on foreign tourists at the national museum that killed at least 21 people.

The presidential announcement came after an emergency meeting of top government and army officials.

The military will be tasked with "patrols at the entrances to, and areas surrounding, major cities" in coordination with the police, a presidential source told AFP.

"We are not under siege," the source added.

The measures also include tightening cooperation among the different branches of the security forces and a review of border security.

No group has claimed the attack by gunmen in military uniforms who opened fire at visitors Wednesday as they got off a bus and then chased them inside the museum.

Twenty foreigners were among the dead, including tourists from Japan, Spain, Colombia, Australia, Britain, Belgium, France, Poland and Italy, Health Minister Said Aidi said.