Mexico authorities started investigation of fake-kidnapping calls to at least 11 federal legislators, including a congresswoman who fainted after being told her son had been abducted.
None of Tuesday's calls, which prompted the speaker of the lower House to suspend the day's session, turned out to be real, congressional officials said.
The calls were all made to phones belonging to members of the governing National Action Party although investigators believe that had more to do with their telephone numbers than their political orientation. The legislators' cell phones begin with the same six numbers and end with two numbers arranged in a sequential series.
"It seems they didn't even know whom they were calling, because they did not refer to any one of the legislators' public positions," House Deputy Speaker Cristian Castano said in a telephone interview.
All of the calls originated from two numbers, the attorney general's office said.
Fake abduction calls, known as "virtual kidnappings," are common in Mexico and elsewhere in Latin America. The perpetrators - some of whom are incarcerated criminals - most often use cell phones, telling whoever answers that they have kidnapped or will kidnap a relative and demanding money.
The callers sometimes put a person on the phone who pretends to be a kidnapped child or other relative. That was the case with the call made to Congresswoman Mirna Rincon, who fainted and fell to the floor in the middle of the legislative session after hearing someone pretending to be her son, Mexican news media reported.