The helicopter carrying Saudi Prince Mansour Bin Muqrin and seven other people was deliberately targeted by state forces because it is believed Bin Muqrin opposed Crown Prince Mohammed Bin Salman’s succession to the throne, informed sources told the New Khaleej.

According to the sources, Bin Muqrin had recently sent a letter to some 1,000 princes urging them to step away from support for Bin Salman’s succession to the throne, pointing out that the youth must take action.

The sources claim the attack sends a clear message to others within the royal family that Bin Salman will stop at nothing to silence his critics and those who oppose him.

Read: Is Saudi’s Bin Salman tackling corruption or making money?

On Sunday evening, Saudi media reported that Saudi Prince Mansour Bin Muqrin and seven other people, including senior government officials and a mayor, were killed in a helicopter crash. Al Arabiya news site released a video of the moments before the Prince’s death as he was heading to the helicopter.

VIDEO: Last video of #Saudi Prince Mansour bin Muqrin, officials before helicopter crash pic.twitter.com/424VsFI9jT — Al Arabiya English (@AlArabiya_Eng) November 6, 2017

The incident came less than a day after authorities arrested 11 princes and 40 former ministers and senior officials, most notably Head of the National Guard Prince Miteb Bin Abdullah and billionaire Prince Al-Waleed Bin Talal for alleged involvement in corruption.