A flag flies above the company's headquarters as Starbucks Corp opens the first upscale Starbucks Reserve store at the Starbucks headquarters in Seattle, Washington, U.S., February 27, 2018. REUTERS/David Ryder

LOS ANGELES (Reuters) - Starbucks Corp SBUX.O on Wednesday revealed details of the employee anti-bias training program that will take place behind closed doors at 8,000 U.S. company-owned cafes on the afternoon of May 29.

Starbucks announced plans to shutter stores and corporate offices to train 175,000 employees after the controversial April 12 arrests of two black men, who were detained for hours after the manager of a Philadelphia Starbucks called police because they had not made purchases and refused to leave.

The arrests of Donte Robinson and Rashon Nelson, who were waiting to meet a friend, sparked protests and calls for a boycott of the coffee chain known for its diverse workforce and liberal stances on issues such as gay marriage.

Starbucks said the first training on May 29 “will serve as a step in a long-term journey to make Starbucks even more welcoming and safe for all.”

It will include videos featuring Starbucks executives such as Chief Executive Kevin Johnson, Executive Chairman and co-founder Howard Schultz, board member Mellody Hobson, hip hop artist Common, store managers and experts from the Perception Institute. Employees also will view a film called “You’re Welcome” by Stanley Nelson and participate in discussion and problem-solving sessions on identifying and avoiding bias in every day situations.

Starbucks said the long-term program is being designed and developed with input from researchers, social scientists, employees and other advisers.

Those partners include consultancy SY Partners - which worked with Starbucks to reinvent itself after a business crisis spawned by the “Great Recession”; the Perception Institute; Sherrilyn Ifill, president of the NAACP Legal Defense Fund; Bryan Stevenson, executive director of the Equal Justice Initiative; and Heather McGhee, president of public policy group Demos.

Since the Philadelphia incident, Starbucks has said it will allow people to sit in its cafes and use its restrooms without making a purchase. It also said it has outlined procedures for dealing with customers who are disruptive, using tobacco, drugs or alcohol or sleeping in its cafes.