America’s aviation regulator has suspended flights by US carriers to Haiti for at least 30 days after three gun attacks in a day on planes departing from the Caribbean nation.

Aircraft from JetBlue, Spirit and American Airlines were all hit by bullets on Monday after flying to the capital, Port-au-Prince.

In the attack on the Spirit plane, a flight attendant suffered minor injuries but no passengers were hurt.

On Tuesday, the Federal Aviation Administration (FAA) issued a Notice to Air Missions (Notam) banning flights because of “safety-of-flight risks associated with ongoing security instability”.

Increasingly violent gang warfare has plagued the poorest nation in the Americas since the assassination of President Jovenel Moïse in 2021. More than 3,600 people have been killed in Haiti since January and more than 500,000 have had to leave their homes, according to the UN.

The country has close relations with the US, which is home to a large Haitian diaspora.

US flights are now not allowed within 10,000ft (3,048m) of the territory and airspace of Haiti.

Separately, the FBI said it had become involved in the investigation into the Spirit shooting.

“The FBI is aware of the incident and working with our law enforcement partners,” it said. “As this is an ongoing matter, we don’t have any further comment.”

All three US airlines involved had already suspended flights independently after the attacks:

• American Airlines announced on Tuesday that one of its planes, American Flight 819, had been struck by a bullet in Haiti. The damage was discovered in a post-flight inspection after it landed in Miami, Florida

• JetBlue Airways Flight 634 returning from Port-au-Prince was discovered with bullet damage after arriving in New York.

• Spirit Airlines Flight 951 from Fort Lauderdale in Florida was hit by gunfire as it tried to land in Port-au-Prince. It was diverted to the neighbouring Dominican Republic, where it landed safely at Santiago Airport.

In a statement, the US embassy in Haiti said it was “aware of gang-led efforts to block travel to and from Port-au-Prince” and said the security situation in the country remained “unpredictable and dangerous”.

Monday’s attacks came just as a new prime minister was taking office in Haiti.

Alix Didier Fils-Aimé said his priority was “restoring security”, according to AFP news agency.

On Tuesday, the US state department urged Haiti’s leaders to put personal interests aside and concentrate on restoring the country.

“The acute and immediate needs of the Haitian people mandate that the transitional government prioritize governance over the competing personal interests of political actors,” a statement said.