A fire that broke out Thursday afternoon in the men’s department of the Target store on Niagara Falls Boulevard in Amherst is being investigated as an arson by Amherst police.

The blaze was quickly extinguished, an Amherst fire official said, but it caused at least $1 million and possibly as much as $5 million in damage to the building’s contents.

“One million is probably a little low, to tell you the truth,” said Detective Lt. Rick Walter of the Amherst police.

Damage to the building was estimated at $2,000, officials said.

One employee was treated at the scene for injuries, authorities said, but not transported to the hospital.

“We are reviewing all security footage from the store,” Walter said. “There were at least, conservatively, 100 people in the store at the time this happened.”

The fire broke out shortly before 3 p.m., authorities said, and the blaze was extinguished in 30 minutes with the help of the building’s sprinkler system.

“Most of the damage was smoke and water,” Walter said.

An investigation into the cause of the fire is under way, but authorities believe the fire may have started when a rack of clothing was set ablaze, officials said.

The Boulevard Consumer Square store, which was closed Thursday evening, is scheduled to reopen today.

Employees at the scene declined to answer questions.

Amherst police are looking for help from the public. Anyone with information is asked to call (716) 689-1364.