President Obama posted a message on Facebook expressing concern over the fatal shootings of Alton Sterling and Philando Castile this week, saying that they are “not isolated incidents” and “symptomatic of the broader challenges within our criminal justice system.”

“All Americans should be deeply troubled by the fatal shootings of Alton Sterling in Baton Rouge, Louisiana and Philando Castile in Falcon Heights, Minnesota,” Obama said in the post. “We’ve seen such tragedies far too many times, and our hearts go out to the families and communities who’ve suffered such a painful loss.”

Obama also was scheduled to deliver a statement on the shootings in Louisiana and Minnesota when he arrives in Warsaw for the NATO summit on Thursday.

“But regardless of the outcome of such investigations, what’s clear is that these fatal shootings are not isolated incidents,” he said. “They are symptomatic of the broader challenges within our criminal justice system, the racial disparities that appear across the system year after year, and the resulting lack of trust that exists between law enforcement and too many of the communities they serve.”

The aftermath of the police shooting of Castile at a traffic stop in Falcon Heights, Minn., was captured by a passenger in his car and streamed live on Facebook. A cell phone camera captured the shooting of Sterling in Baton Rouge.