President Barack Obama appealed for “peace and calm” in Ferguson, Missouri, delivering a message for law enforcement and protesters alike amid the tense situation that’s erupted following the killing of 18-year-old Michael Brown.

“There is never an excuse for violence against police or for those who would use this tragedy as a cover for vandalism or looting,” Obama said Thursday, speaking from Martha’s Vineyard. “There’s also no excuse for police to use excessive force against peaceful protests or to throw protesters in jail for lawfully exercising their First Amendment rights. Here in the United States of America, police should not be bullying or arresting journalists who were just trying to do their jobs and report to the American people on what they see on the ground.”

A man watches as police walk through a cloud of smoke during a clash with protesters Wednesday, Aug. 13, 2014, in Ferguson, Mo. Protests in the St. Louis suburb rocked by racial unrest since a white police officer shot an unarmed black teenager to death turned violent Wednesday night, with people lobbing Molotov cocktails at police who responded with smoke bombs and tear gas to disperse the crowd. (AP Photo/Jeff Roberson)

Brown, who was black, was shot and killed by a police officer in Ferguson over the weekend, triggering unrest in the city over the past several days and a harsh crackdown by police, including the arrest of journalists.

“I made clear to the attorney general that we should do what is necessary to determine exactly what happened and to see that justice is done,” Obama said.

Obama also provided an update on the situaiton in Iraq, saying the situation on Mount Sinjar had “greatly improved” after the humanitarian effort by the United States to aid the religious minorities under siege from Islamic State militants.

“We broke the ISIL siege of Mount Sinjar and we helped save many innocent lives,” Obama said. “Because of these efforts, we do not expect to need an additional operation to evacuate people off the mountain, and it’s unlikely we’re going to need to continue humanitarian air drops on the mountain.”