EXPLAINER: What are the latest clues in China's plane crash?

WUZHOU, China (AP) — Add rain to the list of challenges facing Chinese investigators trying to determine why a passenger jet with 132 people on board crashed in a remote forested region this week.

The search for the black boxes and any survivors — a remote possibility at best — was temporarily suspended Wednesday due to rain on the muddy, charred mountainside.

The China Eastern Airlines Boeing 737-800 was flying at 29,000 feet (8,800 meters) on Monday afternoon when it suddenly nosedived into a gap in the mountains outside the southern Chinese city of Wuzhou.

WHAT HAVE RESCUERS FOUND?

Rescuers with sniffer dogs and drones have found wallets, identity cards and small parts of plane debris. Authorities have given no indication they found survivors, bodies or the plane’s “black box” flight recorders.

Parts of the plane are scattered over a wide area, including the other side of the mountain, state broadcaster CCTV said. The main crash area, now a large barren pit in the forested mountainside, is about half the size of a football field.

Searchers must climb steep inclines as they fan out in the area, which is surrounded on three sides by mountains and accessible by a dirt road.

WHAT ARE INVESTIGATORS SAYING?

Investigators have declined to discuss possible reasons for the crash. Zhu Tao, director of the Office of Aviation Safety of the Civil Aviation Administration of China, said damage to the aircraft was severe, which makes the investigation “very difficult.”

“We cannot have a clear assessment of the cause of the accident with the information currently available,” Zhu said at a Tuesday night news conference, the first since the crash..

Authorities are “carrying out in-depth investigation” of the aircraft’s design and...