Laos military helicopter crash
Twenty-three people went missing after a Laos military helicopter crashed, state media said on July 29, 2015. In this photo, dated May 17, 2014, an officer is seen at another air force plane crash site near Nadee village, in Xiangkhouang province, Laos. Reuters/Stringer

All four crew members and 19 passengers on board a Laos military chopper went missing after the helicopter crashed Monday, state media reported Wednesday, citing the country's defense ministry. The helicopter was bound to the northeastern provinces of Xiangkhouang and Houaphanh.

According to the defense ministry, the crash occurred shortly after 1 p.m., local time, (2 a.m. EDT), state-run Lao News Agency reported. The chopper lost communication with the country’s Aviation Control Centre shortly after leaving the capital Vientiane.

The news agency stated that a rescue operation has been launched for ground search, but bad weather conditions have hampered the aerial search.

The reason behind the accident is not known yet and no details have been released about the passengers.

Such helicopter and plane crashes are not new to the Southeast Asian communist nation. According to the country’s Aviation Safety Network, Laos has witnessed at least 32 air crashes since the 1950s.

In October 2013, a Lao Airlines plane crashed into the Mekong River in Pakse, Champasak province, due to poor weather. The accident killed all five crew members and 44 passengers, including those from France, Australia, Thailand, South Korea, Vietnam, China, Taiwan, Malaysia and the United States. The probable cause of the crash -- the deadliest in the country's history -- was pilot error, according to the authorities.

Last May, five senior officials of the country, including the defense minister, were killed after a military plane en route to the Xiangkhouang province crashed.