Authorities in southern Mexico say they have detained a third person for allegedly tweeting rumors of shootouts and other drug violence.
State prosecutors in the Gulf coast state of Veracruz say police are investigating whether the man is connected with two others detained Thursday.
Prosecutors have said they plan to file terrorism charges against anyone who tweeted the rumors of planned cartel attacks.
The rumors of attacks by the Zetas drug cartel caused chaos in Veracruz city and neighboring Boca del Rio caused chaos as parents rushed to schools trying to retrieve their children.
The tweets warned of attacks on banks and schools, saying that "for each Zeta killed a child will die."
The Mexican government's action echoes what happened in Britain's recent riots, with officials there looking into the role that social networks played in enabling flash mobs and looting to be coordinated.