A lockdown of Capitol Hill was lifted Monday afternoon after gunshots were reported in the Capitol Visitor Center.

Officers shot and wounded a man they identified as Larry Dawson just before 3 p.m., after he entered the north screening area of the Capitol Visitor Center and drew a weapon, Capitol Police Chief Matthew Verderosa said at a press conference.

Dawson, 66, of Tennessee, was charged with assault. He also was arrested inside the House of Representatives in October after he shouted, "I'm a prophet of God."

The suspect was taken to the hospital and was still in surgery at the time of the press conference. An uninvolved bystander suffered minor injuries and was also transported to the hospital.

Verderosa said many details were still being confirmed, including "how many police officers fired their weapons."

US Capitol Police just sent this to Hill staff pic.twitter.com/cTu9GI5Cc5 — Jennifer Bendery (@jbendery) March 28, 2016

There is no reason, he said, "to believe this is anything besides a criminal act." He also said the suspect was known to police, but declined to elaborate on the suspect's identity or how he had come in contact with police.

Charges have not been filed against the suspect, Verderosa said, adding, "It appears that the screening process worked the way it's supposed to."

An Instagram video posted by user Sammy Sanchez appeared to show people being ushered out of the Capitol Visitor Center after the incident:

Not good A video posted by Sammy Sanchez (@ssammysanchez) on Mar 28, 2016 at 12:12pm PDT

Tourists visiting the Capitol at the time were shaken by the incident.

Laurie and Frank Kosker of New Jersey brought their daughters, Emily and Sarah, to the Capitol for a tour Monday. They were heading downstairs from the rotunda when officials told them to head back up and sit down, since they might be there for a while.

They told their kids it was just a drill -- until they all heard loud muffled sounds and felt strong vibrations. That's when they started to get scared and made a plan for what they'd do if anything happened. (There was a wall behind them that they were planning to jump behind and hide.)

To top it off, it was Sarah's 11th birthday.

"We're making memories in Washington," Laurie Kosker joked.

Tourists in the Capitol who didn't hear the shots quickly learned something was wrong when security officials told them to shelter in place. In the crypt, people moved to the sides of the room so officers could move through the center.

Travis Jackson and his family, visiting from New Mexico, were dining in the restaurant near the Capitol Visitor Center when they heard screaming and had to hide under their table.

Tons more people leaving the Capitol after the shooting pic.twitter.com/ol9JHdhAal — Amanda Terkel (@aterkel) March 28, 2016

Marium Baker, who was visiting Washington, D.C., for the first time in years from Illinois, was in the upper balcony of the Senate chamber with her two children when the Capitol went into lockdown. They were told an incident had taken place and were kept in the chamber until the all-clear was given.

“They were very calm, they were very helpful,” Baker said of Capitol Police. She said she didn’t hear any shots.

A woman named Rachel from Indiana said she and her family were just beginning their tour of the Capitol when their guide suddenly diverted the group of about 12 to Indiana Sen. Joe Donnelly’s (D) office, where they were on lockdown for almost an hour and a half. It was the family’s first visit to Washington. “You don’t usually get that on the tour,” said Rachel, who declined to give her last name.

Twin siblings Carol and Carl Archambeault, from Burbank, California, were in the Capitol Visitor Center looking at the self-guided exhibitions as they waited for their 2:40 p.m. tour to start when they heard people yelling, “Go, go, go!”

Carol didn’t hear the gunshots and said she initially thought the noise was a father yelling at his kid. She quickly realized something more serious was happening when she saw people running toward one corner of the building, with Capitol Police rushing past them.

“It escalated very quickly,” said Carl, who was visiting the Capitol for the first time.

The Archambeaults were then led downstairs into a storage facility, which they were told was three levels below the visitor center. They were held on lockdown there for a little over a half-hour. Carol said that despite the presence of heavily armed police, their escorts managed to stay calm and keep the young children in the group from realizing they were fleeing a gunman.

The siblings said they plan to return to the Capitol Tuesday to take a tour.

Senate Minority Leader Harry Reid (D-Nev.), who is in his home state during the Senate's recess, issued a statement on the shooting that recognized the Capitol Police and D.C. Police.

"Thanks to their swift actions, no innocent people were seriously injured and the suspect was quickly taken into custody," he said. "These dedicated men and women work tirelessly to keep us safe, and their bravery was on full display today.”

House Speaker Paul Ryan (R-Wis.) also praised the Capitol Police. “Today we are reminded of the courage and daily sacrifice of the United States Capitol Police," his statement said. "The Capitol is our greatest symbol of democracy, and these officers serve to protect not just those who work there but also the millions of visitors from all around the world who travel each year to see it. This evening our thoughts and prayers are with all those who faced danger today."

D.C. Metropolitan Police tweeted that the shots fired were an “isolated incident”:

There has been an isolated incident at the US Capitol. There is no active threat to the public — DC Police Department (@DCPoliceDept) March 28, 2016

The lockdown Monday afternoon followed a planned security drill earlier in the day, adding to the confusion of some staff and visitors. According to The Associated Press, the White House was also put on lockdown Monday afternoon, but it was lifted by 3:20 p.m. It's unclear whether that was related to the Capitol incident.

Laura Barron-Lopez, Jennifer Bendery, Matt Fuller, Jessica Schulberg and Amanda Terkel contributed reporting.