PORT-AU-PRINCE (Reuters) -The first planeload of Kenyan police arrived in the Haitian capital of Port-au-Prince on Tuesday as part of a new security mission, disembarking a Kenya Airways plane with weapons in hand, according to a Reuters witness.

The officers are expected to lead a mission to tackle raging gangland violence convulsing the Caribbean nation, which has suffered a prolonged period of instability amid a severe humanitarian crisis.

Kenyan police streamed out of the plane at the capital's airport as a small crowd, mostly airport personnel, greeted them on the tarmac.

Kenya volunteered in last July to lead an international force to stem the latest wave of violence to afflict Haiti, where gangs control most of the capital Port-au-Prince while carrying out widespread killings, kidnappings and sexual violence.

But the deployment has been repeatedly delayed by court challenges and a deterioration of the security situation in the Caribbean country, which in March forced its former prime minister to resign.

(Reporting by Harold Isaac; Editing by Aida Pelaez-Fernandez)