Lao military plane carrying top officials including the defence minister crashed on Saturday in the north of the communist country, a Thai official said, without giving details of any casualties.
About 20 people were on board including Defence Minister Douangchay Phichit, the Vientiane governor and other prominent figures, foreign ministry spokesman Sek Wannamethee told AFP.
There was no immediate confirmation from Laos's secretive government.
The officials were believed to be travelling to an official ceremony in the northeastern province of Xiangkhouang.
Laos has had 30 fatal air accidents since the 1950s, according to the Aviation Safety Network.
In October last year a civilian airplane operated by Lao Airlines plunged into the Mekong River in bad weather killing all 49 people on board.
The landlocked country of about seven million people has an authoritarian one-party government and is one of Asia's poorest nations. (AFP)