A Malaysian air force helicopter carrying 10 people crashed in hazy weather in Sarawak state on Borneo island, killing three crew, the army said on Monday.
The Sikorsky S-61A helicopter was ferrying troops on Sunday to a post on the border with Indonesia, just over 600 km (370 miles) north-east of the Sarawak state capital, Kuching.
Five soldiers and two crew members survived the crash, a defence ministry official said.
There have been three previous fatal crashes this year in Malaysia.