BREWER, Maine — Tips that an apartment on North Main Street was the base of a drug-trafficking ring involving bath salts — a dangerous synthetic drug that recently emerged in Maine — led police to raid the place Tuesday afternoon.

Six people were charged after police entered the apartment around 4:50 p.m. and found bath salts, diverted prescription drugs, needles and other drug paraphernalia and weapons, Police Chief Perry Antone said Wednesday.

“The information we obtained is it apparently would be a convenient time” to execute the search warrant, he said, adding the residence had been under surveillance for weeks.

One person faces a bath salts trafficking charge and three others face bath salts possession charges, the chief said. Two others in the apartment were picked up on outstanding warrants, he said, adding that all six have a history of arrests.

Francis Leonard, 48, of Bangor reportedly was found with bath salts, diverted Seroquel and diazepam prescription pills, and hypodermic needles. He was arrested and charged with — among other things — trafficking in synthetic hallucinogenic drugs, based on the amount of bath salts police collected as evidence, Antone said.

The three people charged with bath salts possession were identified as Lisa Turner, 44, of Brewer, Peter McCaffrey, 40, of Hermon and Lynn Cook, 46, of Bangor.

Bath salts are a lab-made drug that can cause hallucinations, convulsions, psychotic episodes and thoughts of suicide, police and medical officials say.

The stimulant and hallucinogenic drugs became illegal in Maine in July, but those caught with the drug are issued a civil offense and dealers face only a misdemeanor charge. State lawmakers stiffened the penalties this week, making possession a misdemeanor and trafficking a felony. Gov. Paul LePage signed the bill into law Wednesday.

Antone said that even though penalties soon will have more teeth, his department wasn’t about to wait.

“Our mission, our goal, with this is to let the community know we’re taking a proactive approach,” Antone said.

The U.S. Drug Enforcement Administration and Congress also both are working to make the main components of the stimulant illegal. While 31 states have banned the drug, it is still available over the counter at convenience stores and head shops in the remaining unregulated states, and online.

How the drugs got to Brewer is not being released, Antone said.

Half of Brewer’s police force, seven officers and three detectives, raided the North Main Street apartment and deputies with the Penoscot County Sheriff’s Office “helped with the perimeter,” Brewer police Capt. Jason Moffitt said Wednesday.

It took several hours to collect and categorize all the evidence, he said, adding that Brewer police Officer Liz Kelley wrote the warrant.

In addition to the bath salts trafficking, Leonard faces two counts of possession of scheduled drugs and possession of hypodermic apparatus, the chief said.

Turner also was charged with illegal possession of a scheduled drug, Cook faces a possession of hypodermic apparatus charge, and McCaffrey has three additional charges: possession of a dangerous knife, sale and use of drug paraphernalia, and violating his bail conditions.

Richard Curtis, 38, of Bangor and Amanda Dinsmore, 28, of Howland both were arrested on outstanding warrants. The warrant for Curtis was on a prior possession of scheduled drugs charge, Antone said.

Dinsmore, Curtis, Leonard and McCaffrey were arrested and taken to the Penobscot County Jail.

Dinsmore and Curtis were released at court on Wednesday, and Leonard and McCaffrey remained in jail Wednesday evening, a jail official said. Turner and Cook were not arrested.

Brewer police, who had not seen the drug six months ago, are dealing with bath salts users three to five times a week, on average, said the police chief, who has been a police officer for 30 years.

“This particular drug … is probably one of the scariest substances I’ve seen on the streets,” Antone said. “It’s because the people on it are so unpredictable and you can’t reason with them. It’s a very dangerous drug.”