Conservationists in Pakistan have asked Unesco to stop part of a cultural event being held on a World Heritage site.

The group of scholars and archaeologists say the opening ceremony of the Sindh cultural festival could damage the ruins of Mohenjo Daro.

It is the world's oldest surviving city and dates back to the pre-Hindu Indus Valley civilisation.

The government insists that it is taking the utmost care not to damage the site.

Shahzeb Jillani reports from the site.