At least five people died and 12 were injured yesterday during the ongoing confrontations.
Venezuelan President Nicolás Maduro responded from Caracas by accusing the U.S. of pressuring countries to side with it by threatening to withdraw financial aid and even impose sanctions.
On Saturday, accusations of fraud and corruption to keep Daniel Ortega in power pressured the chief of the Supreme Electoral Council, Roberto Rivas, to resign.
Ricardo Anaya and the PAN have denounced the investigation as a plot by current president Enrique Peña Nieto and his party.
The case resonates with the 43 disappeared students in the southern state of Guerrero in September 2014.
A single mother of two, Francia Márquez Mina led a successful fight to reverse a multinational gold mining concession that would have forced the relocation of her home town of La Toma.
The kidnap apparently took place last week, either on Wednesday or Thursday, allegedly before the three journalists that the group had in its power were killed.
President Trump was the first U.S. president to skip the summit since Bill Clinton founded it in 1994.