SAN ANTONIO, TEXAS (AP) -- A dozen alleged members of the Texas Mexican Mafia prison gang have been accused of murder and extortion in border communities.

The men were indicted on racketeering charges and accused of murder, drug trafficking and extorting drug dealers.

The U.S. Attorney's Office in San Antonio said the accused enforced a 10 percent tax on drug dealers with robbery and violence around Del Rio and Eagle Pass.

The indictment was unsealed Thursday after six of the defendants were arrested; the others were already in custody.

Authorities say the Mexican Mafia began as a prison gang in the early 1980s, later expanding through associations with street gangs on the outside.

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