CARACAS, Venezuela (AP) — The Carter Center said it was unable to verify the results of Venezuela’s presidential election, blaming authorities for a “complete lack of transparency” in declaring Nicolas Maduro the winner without providing any individual polling tallies.

The statement Tuesday night by the Atlanta-based group is perhaps the harshest rebuke yet of Venezuela’s chaotic election process because it comes from one of just a handful of outside groups invited by the Maduro government to observe the vote.

“The electoral authority’s failure to announce disaggregated results by polling station constitutes a serious breach of electoral principles,” the Carter Center said. The group, which had a technical mission of 17 experts spread out in four cities across Venezuela, added that the election did not meet international standards and “cannot be considered democratic.”