NAIROBI (Reuters) - The first Kenyan police officers assigned to a mission to tackle rampant gang violence in Haiti are leaving Kenya imminently, four officers on the mission and a former police officer said.

Kenya volunteered last July to lead an international force to tackle violence in the Caribbean nation, where gangs control most of the capital Port-au-Prince and have carried out widespread killings, kidnappings and sexual violence.

The deployment has been repeatedly delayed by court challenges at home and a deterioration of security in Haiti, which in March forced the acting prime minister to resign.

Four officers, who asked not to be named because they were not authorised to speak to the media, said their weapons and personal belongings had been collected on Sunday evening to be loaded onto the plane.

An initial contingent of several hundred officers will deploy before the remainder of the 1,000 officers join them, the four officers said. They said they expected to stop over in a third country before reaching Haiti.

A former police officer in contact with members of the mission said the plane would depart on Tuesday.

Kenya's government spokesperson did not respond to a request for comment.

In addition to Kenya, Jamaica, the Bahamas, Barbados, Chad, Bangladesh have pledged personnel to the 2,500-strong mission, which is being funded primarily by the United States.

(Reporting by Edwin Okoth and Aaron Ross; Editing by Kevin Liffey)

By Edwin Okoth and Aaron Ross