March 4 (Reuters) - Deadly fighting between armed gangs and police escalated in Haiti this week, with gang alliance leader Jimmy Cherizier issuing a call to topple the unelected and largely absent government.

The 46-year-old Cherizier, alias "Barbeque," was formerly an officer of the Haitian National Police force. As a police officer, he is alleged by the United Nations to have played a role in multiple massacres, including the killing of over 70 people in 2018, when over 400 homes in the capital's La Saline neighborhood were set on fire.

Cherizier, who is originally from the Delmas area of Port-au-Prince and often makes public appearances in a beret and camouflage, gun in hand, went on to announce the creation in 2020 of a gang alliance. Headed by him, it brought together nine capital area gangs and is called G9 Family and Allies.

In 2021, then-President Jovenel Moise was assassinated, and Cherizier urged protests, accusing opposition leaders and police of masterminding his murder. U.S. prosecutors say there was a conspiracy to replace Moise with a Florida pastor while a Haiti judge has pointed the finger at Moise's widow.

In the wake of Moise's murder, the security situation in Haiti deteriorated further.

Cherizier catapulted the G9 alliance to international notoriety after taking control of Haiti's main fuel port, essentially holding the country hostage as transport was frozen and hospitals lost their energy supplies.

G9 ended the blockade over a month later, while Prime Minister Ariel Henry began rallying international support for a "rapid" U.N.-backed mission to help defeat some 200 gangs of growing influence in the capital.  The U.N. ratified the force a year later, but many countries have been slow to volunteer support, wary of entanglement given Henry's unelected status and a checkered history of international intervention in Haiti.

Meanwhile in Port-au-Prince, gangs were coalescing around G9 and another alliance known as G-Pep, which organized crime analysts say has links with Haitian opposition parties.

Despite reports of a G9-G-Pep truce last July, fighting continued between the gangs, as well as with police and vigilante groups formed in the absence of state protection, forcing hundreds of thousands from their homes.