According to a (Spanish-language) report in the daily newspaper El Diario de Yucatán, the Pirates on Tuesday signed some number of "prospects" (plural) under control of the LMB's Leones de Yucatán. As its source, the paper cited a statement made at a press conference staged by the Leones. No specific information on the players was available. As soon as I learn more, I'll add an update.
The LMB staged a prospect showcase last week in Veracruz, and the Pirates were reported as being one of the teams in attendance, so it's possible that one or more of the signings might be players who performed there. That's pure speculation on my part, though.
With the cap on international signings coming into effect later this year, MLB teams have a strong incentive to spend for amateur talent during the remaining portion of the current signing period.