Investigators probing the crash of a China Eastern Airlines jet are examining whether it was due to intentional action taken on the flight deck, with no evidence so far of a technical malfunction, two people briefed on the matter said.

The Wall Street Journal reported earlier Tuesday that flight data from one of the Boeing 737-800's black boxes indicated that someone in the cockpit intentionally crashed the plane, citing people familiar with US officials' preliminary assessment.

Boeing Co, the maker of the jet, and the US National Transportation Safety Board (NTSB) declined to comment and referred questions to Chinese regulators.

The Boeing 737-800, en route from Kunming to Guangzhou...