Casey Nolen and Brandie Piper

KSDK-TV, St. Louis

FERGUSON, Mo. — Five protesters were arrested and some businesses were damaged Tuesday night after a memorial to Michael Brown was destroyed in a fire. The confrontation reignited tensions in the St. Louis suburb that was rocked by violence this summer after Brown, an unarmed teenager, was shot by a Ferguson police officer.

During a news conference Wednesday, Capt. Ron Johnson with the Missouri State Highway Patrol said two St. Louis County police officers were injured during the unrest.

Johnson said one of the officers was hit just underneath his eye with a rock. He is expected to recover.

The unrest started Tuesday when a beauty supply store was looted and vandalized by several people attempting to haul out a cash register. Johnson said the manager said this was the third time the store had been broken into in the last six weeks.

Police responded to the break-in and then several gunshots were heard and approximately 200 people gathered at the site where demonstrations were held after the Aug. 9 shooting of Brown, 18, by Ferguson police officer Darren Wilson.

After the break-in, a fire was reported at a restaurant on Carson Road. Johnson said the investigation shows gasoline appears to have been poured around the restaurant. He said the fire was put out by Ferguson firefighters.

Some protesters said they were in the streets because the makeshift memorial to Brown burned earlier in the day. Protesters said they believed it was set intentionally.

The fire started around 6:45 a.m. CT Tuesday on Canfield Drive, the street where Wilson killed Brown, said Capt. Jeremy Corcoran with the Ferguson police.

Johnson said the fire started small enough to have been put out with a cup of water, but instead of acting, some people stood watching the fire for 11 minutes until police and firefighters arrived. He said the cause of the fire has not yet been determined, but he doesn't believe that a police officer started it. He says a full investigation is underway to determine the cause.

Later Tuesday, residents later rebuilt the memorial. The blaze angered many people who live near the scene. One man said it was like a grave being desecrated.

Around 12:15 a.m., unpeaceful people started to flash lights into the eyes of police, shouting about shooting officers and burning down the town, Johnson said Wednesday. He said the protesters were positioning themselves close to officers, so the decision was made to disperse the crowd. Johnson said when they attempted to break up the group, some started throwing bottles, rocks and other items at police, injuring two officers.

"This behavior will not be tolerated," said Johnson.

The unrest continued, Johnson said, when someone near Canfield fired shots at the officers. He said he saw the muzzle flash from the gun and sought shelter. Officers were wearing bulletproof vests, but Johnson said a lot of the heavy equipment used during the unrest in August was not used Tuesday, but they will start to respond to the area in riot gear if it becomes necessary.

Johnson also said a Molotov cocktail was thrown at a parking facility.

"We cannot have nights like last night," said Johnson.

Of the five people arrested for failing to disperse, Johnson believed one person also is facing assault and inciting a riot charges.

Brown's death led to weeks of protest and unrest in the St. Louis suburb. After a month without an arrest, Brown's parents and activists questioned why Wilson had not been indicted in the killing.

At the time of the shooting, witnesses in the area said Brown had raised his hands to surrender as he was shot. A state grand jury and the U.S. Department of Justice are continuing to investigate.

Contributing: The Associated Press