TROY — A multi-agency arson task force is looking at links between six arson cases in North Central during the past month and the unsolved arson fires that lit up the neighborhood in 2012, city officials said Tuesday.

Mayor Patrick Madden called a press conference at City Hall to ask for the public's help in solving the fires that have targeted vacant buildings.

"While it is too soon to know if there is a connection between these events, I continue to have great confidence in our public safety officials, who will exhaustively examine all leads in the course of their investigation," the mayor said.

The most recent fire occurred overnight Monday at 61 Sixth Ave., where a shed was set ablaze. Fire Chief Thomas Garrett said the original emergency call was for a house burning.

Officials declined to discuss specifics of the causes of the recent rash of fires, but in 2012 nine fires were set during the summer — all in the early-morning hours, at the rear of vacant buildings that were accessible via alleys. The fires were typically started with gasoline.

Police are doubling their patrols in North Central and enforcing the city curfew in the neighborhood, Chief John Tedesco said. At any time, eight to 16 officers will be in North Central.

As part of the current investigation, Tedesco said the task force is revisiting its lists of suspects from 2012. In addition, the task force is conferring with the state Office of Corrections and Community Supervision to look at recent prison parolees and contacting neighboring jurisdictions in the Capital Region.

Tedesco said there may be one arsonist, though it was possible one or more copycats could also be setting fires.

Investigators do not have any video footage from the vicinity of the fires. Tedesco said the task force is asking anyone with surveillance video in the areas of the fires to contact the police department. Residents who see something suspicious in or around a vacant building are asked to call police at (518) 270-4411 or to call 911 in an emergency.

The task force includes the city's fire and police departments; the U.S. Bureau of Alcohol, Tobacco and Firearms; State Police; and the state fire investigations unit.

As part of the increased patrols, officers have been ordered to write up contact reports on anyone encountered late at night, especially walking in the alleys, Tedesco said.

Police spokesman Capt. Daniel DeWolf said a person who is not a suspect in a crime has the right to continue on his way.

"You can always make an inquiry to people," DeWolf said. "It's not going to be stop-and-frisk," he said, referring to a New York City policing policy criticized in many quarters for targeting people of color.

Molly Kovel, a senior staff attorney for the New York Civil Liberties Union who focuses on law enforcement, said Troy's new policy to stop anyone found outside "sounds incredibly problematic."

"They vast majority of the people in that neighborhood are law-abiding citizens and are now suffering" as a result of the arsons, Kovel said. "They are essentially being held to suspicion for existing in their neighborhood, which they probably can't afford to move out of."

Kovel said that, absent a exceptional circumstance, such as a kidnapping or terror attack, "these types of crime-solving techniques are hard to do within constitutional grounds."

Police can stop someone when they have reasonable suspicion the person has committed, is committing or is about to commit a crime, she said.

But if police stop someone without reasonable suspicion they are involved in a crime and the person feels as if they cannot walk away because, for example, the officer has their ID card or they are surrounded, the stop could be ruled unconstitutional, Kovel said.

When police departments implement such policies, she added, "it tends to result in the community feeling besieged" and less likely to cooperate with this or any investigation.

DeWolf noted that Troy has for several years had a juvenile curfew that makes it illegal for children to be on city streets without an adult from 10 p.m. to 6 a.m. Sunday through Thursday or from 11 p.m. to 6 a.m. on Friday and Saturday.

If the child is 15 years old or younger, the parent will first be warned and, if the city ordinance is violated again, police will call the Rensselaer County Department of Social Services. If the child is 16 or 17 years old, they will be arrested and face a $25 fine and 100 hours of community service.

The NYCLU's Kovel was similarly critical of the youth curfew, saying it "essentially heightens (children's) interactions with police."

Madden said the city may reallocate resources to North Central to raze vacant buildings in an effort to eliminate the arsonist's targets.

The city Bureau of Code Enforcement has been directed to inspect vacant properties to make sure that they are sealed as required by city law. Madden said residents who see unsecured properties are asked to call code enforcement at 518-279-7180 during business hours and 518-270-4404 at other times.

The city also is asking residents to report suspicious activities and person by calling 911 so that a police officer can respond.

There are 572 vacant buildings in Troy. Fifty are owned by the Troy Community Land Bank and 54 are owned by the city.

In the last year and a half, 45 blighted buildings have been removed from city lists. Sixteen of those buildings were demolished, the mayor's office said.