Oct 27 (Reuters) - El Salvador has sent about 1,000 troops to Haiti after four Salvadoran members of a UN-backed security mission went missing in a gang ambush on the outskirts of the capital on October 18, a security official in Haiti told Reuters ‌on Tuesday.

The troops’ arrival aboard flights in recent days dramatically expands the Central American nation’s role in Haiti’s long-standing gang conflict. Yet it remains ‌unclear who will command the new Salvadoran contingent, how long it will stay in Haiti or whether more forces will follow.

Neither the Haitian nor Salvadoran government immediately responded to requests for comment. The ​official in Haiti spoke on condition of anonymity because of the sensitivity of the security situation.

The deployment comes as the UN-backed Gang Suppression Force has reached about 2,000 personnel, just over a third of its planned strength a year into its mandate, with little improvement in Haiti’s security.

Armed gangs in Haiti have meanwhile expanded their influence over the capital and surrounding regions through extortion and brutal attacks that have displaced nearly 1.5 million people.

Haiti’s leaders have sought international security support since 2022, despite the country’s fraught ‌history of foreign intervention. Gangs’ influence grew rapidly after ⁠the 2021 assassination of President Jovenel Moise, deepening an insecurity crisis that has caused authorities to repeatedly delay elections.

Pierre Esperance, head of Haiti’s National Human Rights Defense Network, welcomed the unusually rapid Salvadoran deployment and said he hoped it would help stop ⁠gangs from terrorizing civilians. But he warned that any operation must avoid harming residents trapped in gang-held neighborhoods.

“Not everybody living in gang-controlled areas are gangsters,” he said.

President Nayib Bukele last week announced a military operation to recover the missing Salvadorans, who remain unaccounted for since jumping from a burning vehicle during the ambush. He has not said how many troops ​would ​be sent.