The deadly crash of a China Eastern Airlines 737-800 could set back Boeing's efforts to regain ground in the world's biggest aircraft market and deliver more than 140 of their 737 MAX jets already constructed for Chinese customers.

The 737-800 that crashed on Monday does not have the equipment that led to 737 MAX crashes more than three years ago, but that may not make a difference to Chinese passengers and a national regulator known for scrupulous safety requirements.

China Eastern said the cause of the crash was under investigation. Such accidents typically involve multiple factors, and experts warned it was far too early to draw any conclusions on the potential causes, especially in light of the scarce information available.