In a bid to block U.S.-bound migrants, Panama has installed barbed-wire fencing along the Darien Gap, sparking panic among migrants trying to cross the jungle that links South and Central America — but not necessarily stopping them.

Videos of the barbed-wire barriers appeared as early as June 27 in WhatsApp groups for people planning to migrate to the U.S., causing users to ask who was behind the move and if they could still get across the jungle. Since then, the Ministry of Public Security…