New York Mayor Bill de Blasio implored protesters on Monday to wait until after the funerals of two policemen shot dead in an ambush before resuming rallies that have roiled the city and beyond over the deaths of black men during violent encounters with police.

But de Blasio's plea was quickly dismissed by several activist groups that vowed to continue protests that have stirred the city daily after grand juries chose not to indict police officers who killed Eric Garner in New York and Michael Brown in Ferguson, Missouri.

But the Rev. Al Sharpton, the civil rights activist representing the families of Garner and Brown, said de Blasio's call was too nebulous to heed.

"Is a vigil a protest? Is a rally?" Sharpton said in a telephone interview, calling de Blasio's comments "an ill-defined request."

Sharpton, who joined Garner's relatives over the weekend to denounce the slaying of the officers, said he would not change planned prayer vigils at the scene of Garner's death and elsewhere over the coming days to mark the family's first Christmas without him.