Dozens of people were arrested overnight in Ferguson, Mo., on the first night National Guard troops were deployed to stem two weeks of violence after an unarmed black teen was shot and killed by a police officer.

Protesters fired shots and hurled bottles at police, according to the St. Louis Post-Dispatch, and officers responded with sound cannons.

Multiple volleys of tear gas were also reported.

At least 31 people were arrested, and at least two people were shot during the protests that extended into Tuesday morning, according to Capt. Ron JohnsonRonald (Ron) Harold JohnsonOvernight Cybersecurity: Panel pushes agencies on dropping Kaspersky software | NC county won't pay ransom to hackers | Lawmakers sound alarm over ISIS 'cyber caliphate' GOP chairman warns of ISIS's ‘cyber caliphate’ Overnight Finance: House approves motion to go to tax conference — with drama | GOP leaders to consider Dec. 30 spending bill | Justices skeptical of ban on sports betting | Mulvaney won't fire official who sued him MORE, who is leading the Missouri Highway Patrol's security presence there.

Johnson said no police officer fired a weapon Monday night, despite coming under what he called "heavy gunfire," according to reports. Johnson did not know the two victims’ conditions but said police used armored vehicles to pick them up.

Johnson said some of those arrested were residents from as far away as California and New York.

"I'm telling you, we're going to make this neighborhood whole," Johnson said, according to CNN. "And I am not going to let criminals that have come out here from across this country or live in this community define this neighborhood and define what we're going to do to make it right."

The violence came just hours after President Obama announced that Attorney General Eric HolderEric H. HolderFBI director defends agency after Trump attacks: It's an 'honor to represent you' FBI agents fire back at Trump: Saying we're not dedicated is 'simply false' Holder hits back at Trump: The FBI’s reputation is not in 'tatters' MORE would travel to Ferguson as part of the Justice Department’s investigation into Michael Brown’s shooting.

Holder will meet with law enforcement and other officials.

Obama also pleaded for calm during remarks at the White House.

"While I understand the passions and the anger that arise over the death of Michael Brown, giving into that anger by looting or carrying guns, and even attacking the police, only deserves to raise tensions and stir chaos. It undermines, rather than advancing justice," Obama said.

Obama said most people in Ferguson were "peacefully protesting." But he warned the "small minority of individuals" who have been carrying guns, looting and attacking law enforcement officials "serves to raise tensions and stir chaos."

Holder on Monday asked for patience from the American public.

Holder said he was troubled by the “selective release” of information from other ongoing investigations of the shooting, which has touched off unrest and looting in the town.

— Mario Trujillo contributed to this report, which was updated at 7:05 a.m.