NEW: El Salvador President Nayib Bukele launches military operation in Haiti, threatens to eviscerate Haitian gangs as he did to gangs in El Salvador if they don't return hostages. The statement came after four Salvadoran men were kidnapped by Haitian gangs. "Today's attack is nothing compared to what is coming if we do not get all four hostages back alive," he said. Bukele says the four Salvadoran men are aviation technicians. "They were kidnapped in a cowardly manner while returning after buying food at a market in the area. "That is why, today, we have launched a military operation to rescue them. We have a single objective: to bring our four compatriots back home alive, without any harm." Bukele then issued a warning if gang leaders harm any of the men. "I want you, the gang leaders, to understand one thing very clearly: today's attack is nothing compared to what is coming if we do not get all four hostages back alive..." "And do not take our word for empty threats. We have already finished with the gangs in El Salvador, and we can finish with you too..." "Return our four compatriots to us alive, without any harm, and everything will go back to how it was before the kidnapping."