WASHINGTON, United States (AFP) – US President Barack Obama on Wednesday called the mayors of Tulsa and Charlotte, where the shootings of two black men by police have reignited summer-long racial unrest, urging a calm response to protests.

“Both mayors provided the President with an update on the situation on the ground and the protests in their cities,” a White House official said about Obama’s conversations with Mayor Dewey Bartlett of Tulsa and Mayor Jennifer Roberts of Charlotte.

“The President and both mayors reiterated that any protests should be conducted in a peaceful manner and that local law enforcement should find ways to calmly and productively engage those protesting.”

Terence Crutcher was shot dead by police in Tulsa, Oklahoma last Friday, and Keith Lamont Scott was killed by law enforcement in Charlotte, North Carolina on Tuesday.

Violence and looting overnight in Charlotte injured at least 16 officers and several demonstrators.

“The President expressed his condolences to both Mayors on the tragic events and affirmed the Administration’s commitment to provide assistance as needed,” said the White House official.

These are just the latest in a series of fatal police shootings — from Baton Rouge, Louisiana to St. Paul, Minnesota — that have left the African American community demanding law enforcement reforms and greater accountability.

Presidential candidates Donald Trump and Hillary Clinton were quick to weigh in.

“Keith Lamont Scott. Terence Crutcher. Too many others. This has got to end. -H,” tweeted Democrat Clinton, signing the post herself.

After calling to “make America safe again” in a tweet, Trump suggested Wednesday that the Tulsa officer who shot Crutcher had “choked.”

“I don’t know what she was thinking,” the Republican said, speaking at an African-American church in Cleveland, Ohio.

“Did she get scared? Was she choking? What happened?”