LANSING (AP) -- More than 200 American Red Cross workers in Michigan are on strike in a dispute related to contract negotiations.

The strike caused several blood drives across northern Michigan to be cancelled or rescheduled.

The American Red Cross Great Lakes Blood Services Region received notices of intent to strike from staff members represented by the Office and Professional Employees International Union Local 459 and Teamsters Local 580. The Great Lakes region covers more than 60 counties.

Friday marks the third time the unions have gone on strike in the past two years.  Red Cross blood workers and nurses called a strike last September. The group picketed for two days over benefits.

The Teamsters union said in a statement Thursday night announcing the strike that staffing concerns and health care benefits are among the reasons for the labor action.

The following is a statement from the American Red Cross:

The Office and Professional Employees International (OPEIU) Local 459 and Teamsters Local 580 initiated a work stoppage in the Great Lakes Blood Services Region at 8 a.m. today. About 210 of the 287 employees represented by these unions are participating in the labor action. The Red Cross is disappointed that the unions have chosen to strike.

This is the third time these unions have gone out on strike in the past two years. The Red Cross believes it is irresponsible for these unions to strike yet again. A labor disruption in our area may very well have a negative impact on patients who rely on blood donations. In the Great Lakes Region alone, approximately 700 blood donations are needed each day to meet the needs of accident victims, cancer patients, and children with blood disorders. These patients and others rely on blood products during their treatment.

The Red Cross will do all it can to continue to meet the needs of hospitals and patients in the Great Lakes Region during the work stoppage. Our national inventory allows us to transport blood to wherever it is needed, and we will seek additional donations in areas not affected by the strike.

Health benefits have been the biggest issue in our negotiations with the union. The Red Cross has put forward contract proposals consistent with the benefits package provided locally to our non-union employees, which were declined. The Red Cross has reached agreements on 18 other union contracts since July 2011. These agreements show that we are committed to reaching successful resolution to negotiations.

Blood drive schedules in the Great Lakes Region will be modified during this work stoppage, and we are asking blood donors to call 1-800-RED CROSS or check online at redcrossblood.org to determine the status of their blood drive. The strike does not affect services provided by local Red Cross Chapters.

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