People serving in the military are banned from joining any overseas non-governmental organization (NGO), according to a Chinese People's Liberation Army (PLA) regulation, reports said Monday.

The regulation issued by the PLA's General Political Department took effect September 1.

"It was out of confidentiality concerns," Song Zhongping, a Beijing-based military expert, told the Global Times.

Overseas NGOs refer to non-governmental and non-profit groups legally established abroad, including associations, academic societies, chambers of commerce, foundations, research institutes, the PLA Daily reported Monday.

Many foreign NGOs are actually set up to steal military information by recruiting Chinese soldiers, which have happened, Song said.

He added that some NGOs attempt to brainwash soldiers into conducting "peaceful evolution."

Joining foreign NGOs is politically sensitive and the PLA has to remain united, said the working group in charge of implementing the regulation.

Fang Gongbin, a professor at China's PLA National Defense University, told the Global Times that soldiers joining overseas NGO is uncommon.

Organizations or associations under the PLA which have not registered with the Ministry of Civil Affairs will be dissolved, including those posing as research centers and hobby-oriented clubs, according to the working group.

Many of the associations, which have no essential functions, were set up primarily to feed the vanity of senior military officials, Song said.