Legal firearm owners in Maine are now allowed to carry concealed handguns without a permit in the state thanks to a new law effective Thursday. 

The statute, referred to by Second Amendment rights advocates as a "constitutional concealed carry," applies to both residents and non-residents who are 21 or older, or military members age 18 or older, reported the Associated Press. That means that anyone who is not otherwise banned from possessing a firearm can now carry a concealed handgun in the state without a permit.

The law also authorizes a person to possess a loaded pistol or revolver while in a motor vehicle, trailer or other vehicle being hauled by a motor vehicle.

Firearms are still prohibited in a number of places, including courthouses, schools, state parks, federal buildings and on private property when banned by the land owner.

Before the law went into effect, a gun owner first needed to obtain police-issued permit before being allowed to carry a concealed handgun. To get the permit, applicants had to go through background checks, have fingerprints taken, and fill out six pages of question about criminal history, domestic violence investigations, mental health disorders and drug use. Applicants were also required to present proof that they took a gun safety course and pay a $35 fee, explains Bangor Daily News.

Anti-gun advocates and some law enforcement officials have expressed concern about the law.

The police chief of Portland, the state's largest city, issued a warning Thursday, saying that police officers and the community are now much less safe due to the law.

"This is a poor piece of legislation that we're all about to suffer through," Portland Police Chief Mike Sauschuck said, according to local news station CSH6 Portland.

Ryan Reardon, the sheriff of Interim Kennebec County, said that while he has "some concern," he generally supports the law and thinks the "scrutiny for weapons should be at the point of purchase," reported Portland Press Herald.

Gun rights advocates say that people are making much ado about nothing. "People think all of a sudden it's going to be the wild, Wild West," Jeff Zimba, a firearms policy consultant and gun safety instructor who testified in support of the new laws, told the Bangor Daily News. "We're finding just the opposite -- people are signing up for safety courses. They want more education. They're all saying doomsday, but we're seeing just the opposite."

Alaska, Arizona, Wyoming and Kansas have passed similar laws, while Vermont has never required a concealed carry permit. New Hampshire also passed a similar law to the one enacted in Maine, but it was vetoed by Gov. Maggie Hassan.

Two other laws took effect in Maine Thursday, one repealing the ban on switchblades and similar automatic knives, and the other allowing hunters to use noise suppression devices on guns.