Looting in Philadelphia.

(CNN) -- All Philadelphia liquor stores closed Wednesday over the looting of several stores shortly after the end of a series of peaceful protests against a judge's decision to dismiss all charges against a former Philadelphia police officer in a fatal shooting during a traffic stop.

The Pennsylvania Alcoholic Beverage Control Board closed 49 wine and liquor retail stores (48 in Philadelphia) after 18 stores were looted overnight, Shawn Kelly, the board's press secretary, told CNN.

Although no employees were injured, "some, understandably, were shocked" by the incidents, Kelly said.

"Today, all FW&GS (Fine Wine & Good Spirits) stores in Philadelphia and one in Cheltenham Plaza, Wyncote, Montgomery County, are closed in the interest of employee safety and while we assess damages and losses," Kelly said in a statement. "We will reopen stores when it is safe to do so and when the damage is repaired. It's too early to know how much damage or destruction there was."

The board is one of the largest buyers of alcoholic beverages in the United States, according to its website.

Police will increase resources Wednesday night, a spokesperson told CNN, without elaborating.

As of Wednesday afternoon, 52 people had been arrested, including three minors, after stores throughout Philadelphia's Center City district and liquor stores were looted Tuesday night, said Jane Roh, spokeswoman for the Philadelphia district attorney's office.

The looting followed the end of peaceful protests sparked by a judge's decision to dismiss all charges against a former Philadelphia police officer, Mark Dial, in the Aug. 27 shooting death of 14-year-old Eddie Irizarry, authorities said.

The city's acting police commissioner said he believes the looters were "opportunists" who were not directly related to the protests.

Police respond to reports of looting incidents in Philadelphia on Tuesday. (WPVI)

"This had nothing to do with the protests. What we had tonight was a bunch of opportunistic criminals taking advantage of a situation," Commissioner John Stanford said at an evening news conference.

At least 30 of those arrested, including the three minors, face robbery and larceny charges, Roh said. A police vehicle was vandalized, but there have been no arrests related to that incident.

Police began receiving calls around 8 p.m. local time from businesses that reported they were being assaulted or looted, Stanford said.

The protest over the Irizarry case ended around 7:30 p.m. local time, and while the police department had begun pulling officers out of the area, there were enough to respond quickly when 911 calls about robberies began, Stanford said.

Agents rushed to stores, working to disperse growing crowds of "youth and young adults," Stanford said.

"At one point we were told the crowd came to be about 100 people heading through the downtown area," the commissioner said.

Reports of looting began in the downtown area and then continued in other neighborhoods, according to Stanford.

"We are investigating that there was possibly a caravan of several different vehicles going from one place to another," the commissioner told reporters.

It appears the looters came from different parts of the city, Stanford said, adding that agents were still determining where they came from and how the different vehicles might be connected.

Stanford said it was unclear how many businesses were affected Tuesday, but that stores that were affected included clothing and sneaker stores, luxury stores, wine and liquor stores and pharmacies.

Cellphone video obtained by CNN shows several people in hoodies running and ransacking an Apple store. Different videos captured agents detaining several people outside a Lululemon store, where clothing could be seen lying on the floor.

People outside an Apple store Wednesday after the business was looted the night before. (Matt Rourke/AP)

Elsewhere, agents were seen outside a Foot Locker store, where the window was broken and merchandise was strewn across the floor, a video from CNN affiliate KYW showed.

Investigators will review videos from the area to make more arrests, Stanford said.

"We made arrests and will continue to do so until we have in custody all the individuals who have been responsible for what we have seen tonight," he said.

The reports of looting in Philadelphia come as a wave of retailers, both large and small, say they are struggling to contain crimes that have hurt their bottom line.

CNN's Danny Freeman, Rob Frehse, Rosa Flores and Sara Weisfeldt contributed to this report.

Looting Philadelphia