WUZHOU- Recovery teams deployed drones and thermal imaging equipment Thursday across a mountainous area where a China Eastern plane inexplicably crashed with 132 people on board. Four days after flight MU5735 ploughed into rugged terrain near Wuzhou in southern China, officials are still yet to declare all of the 123 passengers and nine crew dead. More human remains have been found, officials confirmed on Thursday, but the velocity of a crash which punched a crater into the muddy ground and scattered plane parts and passenger belongings across a wide area, has complicated recovery work.  “The depth (of the crater) extends down from the surface to about 20 metres,” Zhu Tao of China’s aviation authority told reporters.  “Most of the aircraft wreckage is concentrated in a core area within a radius of about 30 metres from the main impact point.” Monday’s crash is almost certainly China’s worst air disaster in three decades and President Xi Jinping was swift to order a full investigation into what happened. Wiping tears from her eyes, her arms supported by two men, a distraught relative arrived at the entrance point to the crash area on Thursday morning, according to an AFP reporter.