Preliminary investigations into a November plane crash that killed 33 people show the pilot intentionally brought the Mozambican plane down, an aviation official said.

The Mozambican Airlines plane was bound for Angola with six crew members and 27 passengers. The aircraft went down Nov. 29 in a Namibian national park near the border with Angola.

"There was an intention to crash the plane," Joao Abreu, chairman of the Mozambican Civil Aviation Institute said Saturday.

Possible motives are unknown and investigations will continue, Abreu said. The copilot was in the bathroom at the time of the crash, he said.

Alarm signals can be heard on recovered recordings from the plane, along with the sounds of repeated banging on the cockpit door. - AP