Four off-duty police officers working Saturday night's Minnesota Lynx game at Target Center in Minneapolis walked out after players wore t-shirts supporting the Black Lives Matter movement during warm-ups.

Before their game against the Dallas Wings, Lynx players wore black t-shirts with "Change starts with us, justice and accountability" written on the front, and the names of Philando Castile, Alton Sterling and the emblem of the Dallas Police Department on the back.

Minnesota Lynx players wore t-shirts supporting the Black Lives Matter movement. Getty Images

Castile and Sterling were killed by police officers last week, which led to a series of protests nationwide. One such protest in Dallas turned deadly when five police officers were killed.

Four of the Lynx players also spoke at a press conference before the game.

"We are highlighting a longtime problem of racial profiling," said forward Maya Moore.

The players also spoke out against the "senseless ambush" of Dallas police.

Lynx players wore the names of recent shooting victims and the emblem of the Dallas Police Department. Getty Images

According to the Minneapolis Star Tribune, Lt. Bob Kroll, president of the Minneapolis Police Federation, said he did not know who the officers were, but he supported their decision.

"I commend them for it," he said.

He noted that when the officers are off-duty they are volunteers, and they are under no obligation to complete their shifts.

The four officers also removed their names from a list of those working future games. Kroll said that other officers may take their names off the list as well.

When asked if others will replace those that quit, Kroll responded, "If [the players] are going to keep their stance, all officers may refuse to work there."

UPDATE: According to the Associated Press, the Lynx are not planning on wearing the shirts against the San Antonio Stars in Texas on Tuesday. The team also released a statement:

"The Lynx organization was made aware about the concerns of the off duty Minneapolis police officers," the team said. "While our players message mourned the loss of life due to last week's shootings, we respect the right of those individual officers to express their own beliefs in their own way. ... We continue to urge a constructive discussion about the issues raised by these tragedies."