Way too early to speculate but the majority of the passengers were Chinese about 160 of the 230 passengers. The Chinese have been experiencing relentless terrorist attacks from the Uyghur people from Xinjiang in the far Western China. The most recent attack was a bloody machete wielding mob who hacked up 30 plus people in Kunming, China a whole separate region in Southern, China. There have also occured almost monthly police confrontations and terrorist attacks in Xinjiang. An attempted terrorist hijacking was also carried out last year in Xinjiang on an E-175
but the crew did a valiant job in getting the aircraft on the ground expeditiously and the passengers and crew fought off the attackers. Many of these terrorist attacks go unpublished and are unknown mostly outside of China.