Several leading Pakistani archeologists say a government cultural festival at an ancient site in the country's south is putting the ruins at risk.

Bilawal Bhutto Zardari, the son of assassinated former prime minister Benazir Bhutto, is organizing the event Saturday at Mohenjodaro, where one of the largest settlements of the Indus Valley civilization existed thousands of years ago.

Archaeologist Farzand Masih said Friday that organizers have harmed the site by erecting wooden and steel scaffolds for a stage. Another archaeologist, Asma Ibrahim, said a planned light and sound show could damage the delicate walls.

Authorities insist there was no risk.

A provincial archaeology official, Qasim Ali Qasim, says he is supervising arrangements for the festival to make sure no harm is caused to the site in the southern Sindh province.