Azimio la Umoja One Kenya Coalition has called off Wednesday demonstrations.
In a statement on Monday, Azimio instead asked Kenyans to hold vigil for those who have been killed during the past protests.
"Azimio has made the decision that on Wednesday, rather than go to the streets for a peaceful demonstration as earlier announced, we will hold solidarity parades and vigil for victims of police brutality in various locations in all parts of the country," the statement reads in part.
"We are calling Kenyans to come out and light candles and lay flowers in remembrance of and respect for the victims."
The Coalition said it arrived at the decision after carrying out an operation, which is yet to be completed, entailing summing up the number of deceased persons and injuries from the past demos.
It said their calculations so far show that 50 people died with hundreds sustaining injuries.
It claimed that hospitals have been ordered not to disclose the number of casualties or deaths from alleged police brutality.
It further alleged that many of the victims were shot at close range.
"Some have been shot in the back as they were fleeing or in a position of surrender. The shots have been aimed at the vital organs and delicate parts of the victims like the abdomen, the spine, the chest and the head," it said.
The outfit further said the victims were unarmed.
In memory of the dead, Azimio also asked Kenyans to say prayers during the vigil on Wednesday.
"During the vigils, candle lighting and laying of flowers, we encourage Kenyans to say prayers and read out the names of the victims of police brutality," it said.
It added that it will provide the list of the victims in time for the exercise, urging religious leaders to extend the exercise to Friday, Saturday and Sunday.
"We ask the religious leaders and the people of Kenya to extend this important exercise by dedicating Friday, Saturday and Sunday for prayers in remembrance of the victims of police brutality during the past peaceful demonstrations," the outfit said.
Further, the opposition urged Kenyans to pray that the Hague may intervene and get justice for the victims.
"We ask Kenyans to pray also that the International Criminal Court takes up the matter based on an expanded list of perpetrators that we intend to furnish with the court in due course," Azimio said.