Mexican forces have arrested a senior leader of a powerful vigilante group that has taken up arms to protect locals from a major drug cartel.

Jose Manuel Mireles was detained in the Pacific coastal town of Lazar Cardenas after entering a town with more than 100 armed supporters.

Mireles, who sported a thick moustache and wore a cowboy hat, was a co-founder of Michoacan's vigilante or "self-defence" movement.

He was arrested with "weapons of exclusive military use," the Michoacan state government said via Twitter.

Along with Mireles, more than 100 armed men who claimed to be self-defence force members were also arrested, an army source told AFP, speaking on condition of anonymity.

Mireles entered the town of La Mira on Thursday with some 600 followers armed with automatic rifles. He claimed that the locals had called him for protection against criminal gangs.

Vigilantes in Michoacan, mostly farmers and other civilians, took up arms in February 2013 claiming that the local police was too incompetent or corrupt to protect them from local criminal gangs, especially the cult-like Knights Templar drug cartel.

The government was slow to react, but finally in May 2014 it agreed to give the vigilantes uniforms and weapons and legalise their movement, but vowed to arrest any armed group that failed to register with the authorities.

The rise of the vigilante movement, which has spread to some 30 towns, brought fears that it could turn into a dangerous paramilitary force.

And there has been internal dissent. In May, the council of self-defence forces dismissed Mireles as its spokesperson, saying "recent actions" had cost the lives of five civilians.

AFP