DUBAI: A rescue helicopter crashed on Saturday near the world’s longest zip line in the emirate of Ras Al-Khaimah, killing all crew members, the United Arab Emirates state news agency WAM said.

Sheikh Saud bin Saqr al-Qasimi, ruler of Ras Al-Khaimah, ordered an investigation into the incident that took place at 5:50 pm (1350 GMT).

“The General Civil Aviation Authority announced the crash of an Agusta 139 helicopter during a rescue mission in Jebel Jais in Ras al-Khaimah,” said the report.

The UAE’s National Search and Rescue Centre said there were four people on board.

Videos posted online show the helicopter diving into a tailspin before crashing and bursting into flames in the valley of a rocky mountain.

The UAE comprises the emirates of Abu Dhabi, Ajman, Dubai, Fujairah, Ras al-Khaimah, Sharjah and Umm al-Qaiwain.