Protesters blocked a highway and clashed with police in Charlotte, North Carolina, early on Wednesday morning after officers fatally shot a black man they said had a gun when they approached him in a parking lot.

About a dozen officers and several protesters suffered non-life threatening injuries during an hours-long demonstration near where Keith Lamont Scott, 43, was shot by a policeman on Tuesday afternoon, police and local media said on social media.

Early Wednesday morning, protesters blocked Interstate 85, where they stole boxes from trucks and started fires before police used flash grenades in an attempt to disperse the angry crowd, an ABC affiliate in Charlotte reported.

A group of protesters then tried to break into a Walmart store before police arrived and began guarding its front entryway, video footage by local media showed.

Earlier in the evening, police in riot gear reportedly used tear gas on protesters who threw rocks and water bottles at them as they wielded large sticks and blocked traffic. One officer was sent to the hospital after being struck in the head by a rock, police said.

Charlotte Mayor Jennifer Roberts urged for calm.

“The community deserves answers and (a) full investigation will ensue,” she said on Twitter, adding in a subsequent post, “I want answers too.”

Read More: reuters