"Kerry called Bangladesh Prime Minister Hasina on April 28 to offer US support for the investigation into the attack that killed human rights advocate and US Embassy employee Xulhas Mannan, along with Tonmoi Mahbub, earlier this week," the State Department said.
Kerry also condemned other incidents in a recent spate of violence.
"The Secretary urged Prime Minister Hasina to ensure a thorough investigation of all of these incidents, and to redouble law enforcement efforts to prevent future attacks and protect those who are at risk," the State Department said in a readout of the call.