Haiti’s capital Port-au-Prince is largely shut down amid a wave of violence that started last week with an attack on a prison that freed thousands of inmates.

Residents are now trying to flee the city, or only venturing out for essentials, after authorities imposed a state of emergency. Armed gangs now control much of Port-au-Prince and are wreaking havoc.

Powerful gang leader Jimmy Cherizier, a former police officer known as “Barbecue” accused of human rights abuses, warned on Tuesday that the chaos engulfing Haiti would lead to civil war and “genocide” unless Prime Minister Ariel Henry steps down.

The comments came with Henry still outside the country following a trip to Kenya to request the deployment of a United Nations-backed multinational police mission.

With the country’s main airport under attack, he tried to fly into neighbouring Dominican Republic, which shares the island of Hispaniola with Haiti, but Santo Domingo refused permission for him to land.

Henry was supposed to step down last month. The armed criminal gangs who control large swaths of the country say his failure to do so prompted the launch of a coordinated bid to remove him.

A police academy in Port-au-Prince, where more than 800 cadets train, came under attack on Tuesday. The assault was repelled after the arrival of reinforcements, said Lionel Lazarre of the Haitian police union.

The Haitian government has promised that the security forces will take back control of Haiti. However, the country’s police are notoriously weak and often under-equipped compared with the gangs, meaning kidnappings and other violent crimes are rampant.