Lawmakers in the southern Mexican state of Guerrero approved a measure to incorporate the various community self-defense groups that have popped up in the Pacific coastal region into a new force under authorities' control.

"The rural police groups created in Guerrero communities will operate subordinate to the relevant authorities and institutions," the state legislature said in a statement.

By a vote of 18-11 with two abstentions, the Guerrero assembly approved the state government's package of amendments to the existing public safety law.

Members of the Rural Police are to be selected by their fellow townspeople in a democratic process.

The individual units will be limited to operating within their respective communities except when regular state or municipal police forces request their assistance elsewhere.

Rural Police officers will be paid, armed and equipped by the Guerrero state government.

Community self-defense groups have multiplied over the past year in Guerrero and the neighboring state of Michoacan.

Indigenous communities in both states mobilized to defend themselves against a criminal organization that calls itself "Los Caballeros Templarios" (Knights Templar).

The Caballeros are said to dominate the trade in synthetic drugs bound for the United States, such as crystal meth. But the gang also preys on ordinary people, engaging in extortion, kidnapping and murder.

Militias have been formed in more than a dozen Guerrero municipalities and in the suburbs of the resort city of Acapulco.