The US embassy in Haiti reported gunfire on Monday near its diplomatic compound as it urged bystanders to take cover.
In a travel alert, the US State Department said that gunfire had come from the "rear entrance to the embassy" in Port-au-Prince.
It said the staff had taken shelter inside the embassy.
"If you are traveling to the embassy, find a safe area to shelter," it wrote on Twitter. State Department officials did not immediately have further details on the incident, including whether it was ongoing.
Haiti, one of the world's poorest countries, witnessed widespread riots in February when thousands of people took to the streets demanding better living conditions. Haiti's President Jovenel Moise earlier this month appointed a new prime minister to tackle mounting problems, including insecurity in the capital.