Three people were killed when a gunman fire shots through the wall of a municipal building in a town in north-eastern Pennsylvania during a meeting and then barged into the room, a witness said.

The killer was then tackled by a local official and possibly another person and shot with his own gun.

State police in Lehighton confirmed the three deaths and said the gunman, identified as 59-year-old Rockne Newell, had an ongoing dispute with town officials over the possible condemnation of his unkempt property. They said about 15 to 18 residents and town officials were at the meeting place, a short drive from Newell's property, when the gunfire erupted.

The shooting, in which at least two other people were injured, happened during Ross Township's monthly meeting, Monroe County emergency management director Guy Miller said. The gunman, who appeared to be "shooting randomly", was captured and treated in hospital, he said.

Two people died at the scene, and a third person died after being flown to hospital. Police confirmed that at least one of the dead was a township official but declined to give additional details. A fourth person, a woman, was in surgery with undisclosed injuries.

Investigators said Newell began shooting as he approached the building and continued as he walked into and through it. He then went back out to his vehicle in the car park, retrieved a handgun and went back into the building, firing more shots, police said.

Pocono Record reporter Chris Reber said he was at the township building when a man armed with a long gun with a scope fired through a wall into the meeting place, in a rural area of north-eastern Pennsylvania, about 85 miles (137km) north of Philadelphia.

"The thing that got my attention: plaster flying out, blowing out through the walls. Witnesses would later tell me they saw pictures exploding away from the walls," Mr Reber said in a first-person account to his editors, Marta Gouger and Chris Mele. "I heard more than 10 shots."

He said he crawled out to a hallway, exited the building and took cover behind a vehicle.

"The gunman was this guy wearing a blue Hawaiian shirt," he said. "I saw him go back out to his car, a silver Impala, and get another gun.

"It wasn't real to me until I went back inside and saw people bleeding."

A local official at the meeting grabbed the gunman and subdued him, Mr Reber said.

"(West End Open Space Commission executive director) Bernie Kozen bear-hugged the gunman and took him down," he went on. "He shot the shooter with his own gun."

State police said they believed two people may have subdued the gunman, who was shot in one of his legs.

US Republican Matt Cartwright, who represents the state's 17th District, said he was "appalled at the atrocities that claimed the lives of innocent citizens in Ross Township". He said he had heard about what Mr Kozen did to prevent more bloodshed.

"Mr Kozen is a true hero tonight," the politician said in an emailed statement.

Mr Kozen's wife, reached by telephone at their home, said he was not there and she was unsure when he would be back.

Newell had been in a long-running dispute with township officials over the dilapidated condition of his property, state police Captain Edward Hoke said. The township supervisors voted in February 2012 to take legal action against Newell for violating zoning and sewer regulations, according to meeting minutes posted online.

The ramshackle property includes an old camper van in the front yard filled with wooden pallets, pieces of what appear to be old railway sleepers and rubbish. A garage is leaning and appears close to collapse, and a propane tank sits inside an old dog house.

State police were guarding the property and awaiting a search warrant so they could enter it.

In June, the Pocono Record wrote a story about what it said was an 18-year fight between the township and Newell over his property.

Monroe County Court in August 2012 sided with the township and ordered Newell to vacate and never again occupy or use the property unless he had the permits to do so. The report said Newell had been living out of a car and in abandoned buildings since being ordered to vacate.

Newell told the newspaper he was unemployed for years after an injury from a crash and had nowhere else to go.

"They have no right to kick me off my property," he told the newspaper. "They call my property an eyesore. When I bought it, it was one of only three properties on the entire road that didn't have what they call junk."

Newell was in police custody after receiving medical treatment.