(BALTIMORE) -- A fire and explosion at a suburban Baltimore nail salon that injured seven people was deliberately set by an "emotionally distressed" man, authorities said Tuesday. Four police officers and two emergency medical workers were wounded in the incident.
The suspect, whose name was not immediately released, was critically injured in the blast at the Libra Nails & Spa salon in Windsor Mill about 23 miles northwest of Baltimore, according to the Baltimore County Police Department.
Baltimore County Fire Department officials said the suspect is a former employee of the nail salon, the Baltimore Sun reported.
Police officers responded to a workplace disturbance call at the nail salon, in the Security Station Shopping Center, just after 9 p.m. and encountered the suspect who was refusing to leave business, police said in a statement released to ABC News Tuesday morning.
A police spokesperson told reporters Monday night that officers called EMTs to the scene to examine the "emotionally distressed" man. While the officers and EMTs were inside the salon, the suspect suddenly ran to the back of the business, police said.
"The individual refused commands by officers and proceeded to run into the back of the store where he started a fire that produced an explosion," according to the police statement.
The four police officers and two EMTs were taken to hospitals with minor to non-life-threatening injuries, according to the statement. One officer remained in the hospital Tuesday for further observation, while the other officers and emergency medical workers were treated and released.
The suspect was placed into custody and taken to a hospital with life-threatening injuries, according to the statement.
Charges against the suspect are pending further investigation, police said.
A motive also remains under investigation.
The federal Bureau of Alcohol, Tobacco, Firearms and Explosives and the Baltimore County Fire Department are assisting the probe.
Fire officials said the blaze and explosion were fueled by flammable chemicals, including acetone and nail polish remover, stored inside the business. The fire quickly engulfed the business and prompted fire officials to declare a hazmat situation.
The fire was brought under control at about 10:30 p.m. Tuesday.
ABC News' Chad Murray contributed to this report.