This vehicle was alongside one of the 'migrant caravans' in Mexico. The workers were providing assistance to the illegals, who I think were mostly Haitians that day. Journalist Oscar El Blue has said that many of the Haitians are ex-police/military, and blames the UN for the illegals flooding into both Mexico and the United States.
"The International Organization for Migration (IOM) is part of the United Nations System as the leading inter-governmental organization promoting since 1951 humane and orderly migration for the benefit of all, with 174 member states and a presence in over 100 countries."
https://www.iom.int/