The Puma helicopter went down at a military base in Bogor, West Java, at around 2pm (0700 GMT, 3pm Singapore time) during a test flight, spokesman Bambang Sulistio said.

'The helicopter had just undergone repairs and was being tested to see if it was fit to fly. Seven personnel were in it and two were killed in the crash,' he added.

It was not immediately known what caused the crash. The dead servicemen were technicians from the air force.

'Planes and helicopters must be checked before they are allowed to fly,' Defence Minister Juwono Sudarsono said.

Two special forces troops were killed Monday when an army helicopter crashed in South Cianjur, West Java.

An Indonesian military Hercules transport plane crashed last month as it prepared to land at a base in East Java, killing 101 people.

In April, 24 military personnel were killed when their training aircraft slammed into a hangar at an air base in West Java. -- AFP