Update:

Williamsburg Police arrested a Gloucester man Friday and charged him with possession and using of an explosive device and committing an act of terrorism following the detonation of an improvised explosive device, according to police spokesman Maj. Greg Riley.

Stephen Powers, 30, of Gloucester, was arrested at his home, Riley said. It follows the explosion of the IED around 5 p.m. Thursday in the parking lot between the Berret’s Seafood & Taphouse and Williams-Sonoma.

“I would personally like to thank all the local, state and federal law enforcement partners who worked around the clock to quickly apprehend a potentially dangerous member of the community,” said Williamsburg Police chief Sean Dunn in a statement.

Riley said the investigation will continue, though law enforcement officials believe this is an isolated incident.

Previously:

Those attending the College of William and Mary’s homecoming activities might notice a visible law enforcement presence this weekend after an improvised explosive device detonated Thursday evening. Still, all events are on as scheduled and businesses will be open normal hours.

Federal, state and local law enforcement officials determined Thursday’s explosion was an isolated incident, Williamsburg Police spokesman Maj. Greg Riley said.

“Out of an abundance of caution, the police department is taking additional measures in the area, and guests visiting Colonial Williamsburg or attending William and Mary homecoming events … may see a visible increase in law enforcement presence,” said Riley in a news release.

Homecoming activities began Friday afternoon with the parade and other events, and large crowds gathered downtown and along the parade route.Saturday’s homecoming calendar features the Tribe’s matchup against the top-ranked James Madison.

“If you’re in the area over the weekend, and you see something suspicious, please call the police,” Riley said. “And we’ll check it out.”

Most parking lots downtown had reopened by Friday afternoon, except for Lot P6 behind the Sotheby building, which fronts Francis Street. Law enforcement had still had that taped off late Friday afternoon and kept Francis Street closed between South Boundary Street and North Henry Street until about 6 p.m. Friday, when it reopened to traffic. At least one law enforcement official was on a ladder propped up on the Sotheby building Friday afternoon.

What happened

The explosion took place around 5 p.m. Thursday in the parking lot between Berret’s Seafood & Taphouse and Williams-Sonoma. A caller initially reported a vehicle fire, Riley said.

Law enforcement determined an improvised device caused the the explosion; no one was injured, Riley said.

The Federal Bureau of Investigation and the Bureau of Alcohol, Tobacco and Firearms arrived at the scene at about 9 p.m. Thursday.

Riley confirmed a criminal investigation is underway. It is being aided by the Williamsburg Fire Department, Colonial Williamsburg Public Safety, Newport News Police Department and Virginia State Police.

“There is no indication at this time that there is any additional threat to the public,” Riley said in a briefing Friday afternoon.

The entire parking lot between Francis Street and Merchants Square was closed for much of Friday morning until about 12 p.m. ATF and FBI officers walked the scene inch-by-inch several times during the morning.

Earlier in the morning, Matthew Whaley Elementary School was placed on lockdown for about 45 minutes after a passerby reported a car parked in the area with three propane tanks inside. After finding the car’s owner, Williamsburg Police determined that the person was preparing for a weekend party, and it was not connected to Thursday’s explosion, Riley said.

The school lockdown was lifted around 11:20 a.m., according to Williamsburg-James City County school spokeswoman Betsy Overcamp-Smith.

After light crowds for much of the morning in Merchants Square, more people began filtering into the downtown area. The parking lot was partially reopened by afternoon as the ATF and FBI continued their investigation, digging up the mulch — and later putting it back in place — looking for fragments of the IED and any other evidence, Riley said.

On the scene

Witnesses who heard the explosion describe hearing a loud noise around 5:15 p.m. Thursday.

Stephen Bommer, visiting from New Jersey, said he was sitting in Berret’s outdoor seating having drinks when he heard a loud explosion.

“A large explosion happened out back in the parking lot, Bommer said. “We thought it was a car exploding, but there was a van with a lot of debris on it. … Somebody said it was an underground transformer.”

Bommer said he noticed two people in the car who appeared “pretty shaken up,” and that everyone at Berret’s were keeping their distance from the scene. He said he didn’t notice a fire, but saw what looked to him like dirt and soot on the van near the explosion.

“This is totally out of the normal for Colonial Williamsburg, to have an explosion, quote-unquote, happen in little Colonial Williamsburg,” Bommer said. “I think everybody was just shocked. It was a one-time occurrence. There wasn’t anybody around. Everybody just walked back to the bar and had another drink.”

He said the incident would not deter him from returning to Williamsburg, nor affect his daughter’s college choice — she is visiting W&M.

“We pulled in just after it happened,” said Ron Henderson of Clifton Springs, New York. “There were two vehicles that had mulch on them, and they’re gone now.”

Henderson said he heard the explosion before he parked his rental car behind Berret’s. By the time he left the restaurant around 10 p.m., he said he was unable to retrieve his car and had to return to where he and his wife were staying at King’s Creek Plantation in a taxi.

“Driving up on Henry Street, we heard the bang,” Henderson said. “And we pulled in, there was an open parking spot. I thought, hey, everything’s underground, thought it was a transformer, didn’t think much of it. And (my wife) goes, ‘well, you better move the car.’ Obviously, I didn’t listen to her, and here we are, stuck.”

Henderson said he was surprised at the police presence Friday after what he heard the previous night.

“They said the fire department was in charge of it last night, and I get back here this morning, and you look around, you see the ATF and the FBI, you go, ‘Oh boy,’ I don’t think it was a transformer. There’s something more to this,” he said.