The presidential campaign for Beto O'Rourke targeted social media advertisements at individuals in Mexico, according to Facebook transparency tools.

Facebook has for the past year allowed users to see, using the "info and ads" tab, where a group is targeting its sponsored posts. A screenshot of O'Rourke's page captured by the Washington Free Beacon last Friday revealed he was paying to have certain posts viewed by Facebook users in Mexico.

Among the posts O'Rourke paid to blast out to Mexican users was an invitation to his Tuesday campaign stop at the Jacobs Center in San Diego, Calif. The details are posted on the event page in both English and Spanish.

The O'Rourke campaign did not respond to a request for comment on the Mexican advertising. A Monday review of his campaign's Facebook page found it was no longer advertising in Mexico.

It is unclear why O'Rourke is running ads in Mexico for his campaign to be president of the United States. There is a Democrats Abroad primary that will be held next March, but O'Rourke has made no mention of it thus far on the campaign trail.

A review of the Facebook pages for each of O'Rourke's Democratic opponents for the presidential nomination found that none were running ads targeting anybody outside the United States.

Republican President Donald Trump's campaign page shows he is running ads in both the United States and Puerto Rico, which is part of the United States but categorized separately by Facebook. No other candidate was running ads in Puerto Rico.

O'Rourke is from the border town of El Paso, Texas. He has been a vocal opponent of Trump's proposal to build additional wall on the southern border and has also advocated for removing existing wall.

As a congressman, O'Rourke argued for opening the border between El Paso and the Mexican city of Juarez.