At least 1,301 people died during Hajj, Saudi Arabia says, mostly unauthorised pilgrims who walked long distances in intense heat.

This year's pilgrimage took place during a heatwave, with temperatures at times exceeding 50 C.

More than three-quarters of those who died did not have official permits to be there and walked under direct sunlight without adequate shelter, the official Saudi news agency SPA said.

Some of those who died were elderly or chronically ill, the agency added.

Health Minister Fahd Al-Jalajel said efforts had been made to raise awareness about the dangers of heat stress and how pilgrims could mitigate this.

"May Allah forgive and have mercy on the deceased. Our heartfelt condolences go to their families," he said.

Health facilities treated nearly half a million pilgrims, he said, and some were still in hospital for heat exhaustion.

Saudi Arabia has been criticised for not doing more to make the hajj safer, especially for unregistered pilgrims who have no access to facilities such as air conditioned tents and official hajj transport.