FERGUSON, Mo. -- Police cleared Ferguson of protesters Sunday hours before a state-imposed curfew was set to take effect, throwing tear gas at individuals who were out in the streets over the death of Michael Brown, the unarmed black teenager shot and killed by police officer Darren Wilson on Aug. 9.

What had started out as a loud, party-like gathering -- with protesters honking horns, dancing and yelling -- quickly dissolved into chaos as the midnight curfew approached. Police, equipped with armored vehicles, shields and gas masks, fired tear gas down Ferguson's West Florissant Avenue.

In a press conference early Monday morning, Missouri Highway Patrol Capt. Ron Johnson, who is now in charge of security in Ferguson, said officers were commanded to throw tear gas after members of the crowd began throwing Molotov cocktails at the police. There were also reports of gunfire and businesses being broken into, with workers at a McDonald's reportedly locking themselves in a back room when the vandalism started.

According to Johnson, there were seven or eight people arrested in the protests, and at least two people were injured. He deliberately distinguished between peaceful individuals who came out to rally and people committed to "premeditated criminal acts."

Gov. Jay Nixon (D) announced early Monday morning that he had signed an executive order to send National Guard troops to Ferguson.

"Given these deliberate, coordinated and intensifying violent attacks on lives and property in Ferguson, I am directing the highly capable men and women of the Missouri National Guard ... in restoring peace and order to this community," he said in a statement.

Among those hit with tear gas Sunday was an 8-year-old boy. His mother declined to give an interview, but the crowd rallied immediately around him, attempting to get him water.

Whoa. This kid was just hit with tear gas. Mom is freaking out. #Fergusonpic.twitter.com/5SHrdZvFqV — Amanda Terkel (@aterkel) August 18, 2014

Cassandra Roberts from Richmond Heights, Missouri, came out Sunday night because she thought it was going to be peaceful and she would be able to march in solidarity without any problem.

She said she knew there was a problem when she started seeing everyone running. She went down on her knees and raised her hands in a "don't shoot" motion, but she quickly realized there was a bigger issue and she was being tear-gassed.

"I literally see these little things like, bop bop bop, and smoke is coming up. I got so choked up," said Roberts. "I couldn't even gather myself. I was so mixed up in the smoke. ... It took one of the McDonald's employees to pull me up out of the smoke. My eyes were wide open and I couldn't see a thing. They had to throw milk and water in my eyes. I didn't come down here for this."

Candice Dotson and her 11-year-old son were going back to their car when they were caught up in the beginning confrontations. She wanted to go home, she said, because the crowd was starting to get rowdy, but she never expected to be tear-gassed.

"It was horrible. There were little bitty kids in strollers. He's okay, but he's scared out of his mind," she told The Huffington Post.

Thursday was supposed to be the first day of school for the Ferguson-Florissant School District, but it announced that it was canceling classes for the week due to the continuing unrest.

Although the streets were largely cleared well before it was time for curfew, residents were supposed to be off the streets of Ferguson from midnight until 5 a.m. for the second night in a row. The Huffington Post saw at least four people walking the street get handcuffed by police for being out during that time.

Police handcuff a kid out past curfew. Four people taken in. On W Florissant #Fergusonpic.twitter.com/8SOHXz1TCO — Amanda Terkel (@aterkel) August 18, 2014

The first curfew, imposed by Gov. Nixon on Saturday, was broken by several protesters. One person was shot and seven were arrested during demonstrations early Sunday.

This piece was updated with additional information.

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