Three carriages were consumed by flames from a fire caused by a cooking gas stove and dozens of people jumped from the speeding train to their death in panic.
The fire is believed to have started by a cooking stove onboard. It destroyed three carriages near the town of Rahim Yar Khan in the south of Punjab province.
Prince William and his wife Kate travelled in the colourful vehicle to the historic Pakistan Monument in Islamabad.
"They do not understand that this can go horribly wrong,"the Pakistani Prime Minister Imran Khan said.
Tuesday's powerful 5.8 magnitude earthquake levelled homes and shops and split open roads.
Troops used tear gas and pellet guns on the crowd,which insisted on carrying on with the Muharram procession.
The United Nations'highest court previously ordered Pakistan to stay Kulbhushan Jadhav's execution.
Nearly 2 million people in north-east India have been told they could soon be declared stateless in a mass citizenship check that critics say is anti-Muslim.
India's foreign ministry asserts life is returning to normal in the heavily-militarised territory. Independent news reports suggest otherwise.
The Indian government scrapped Kashmir's autonomy on August 5,bringing the region under direct administration of the federal government.
Those arrested include anti-India protesters as well as pro-India Kashmiri leaders who have been held in jails and other makeshift facilities.