A massive manhunt was under way Thursday for a gunman who a local official said killed at least 22 people and wounded "many" more in mass shootings in the US state of Maine, the deadliest such incident this year.

Police said Robert Card — seen in surveillance footage pointing a semi-automatic weapon with an extended clip as he walked into a bowling alley in the town of Lewiston — "should be considered armed and dangerous." 

Card is a certified firearms instructor and a member of the US Army Reserve, CNN reported, citing law enforcement sources. 

Lewiston city councilor Robert McCarthy told CNN that law enforcement had "confirmed 22 dead, many, many more injured", with local media reporting shootings had occurred at multiple locations. 

Swathes of Lewiston were locked down, with businesses urged to shutter and people ordered to shelter in place, as the scourge of horrifying gun violence once again ripped through an American community.

Maine public safety official Mike Sauschuck said he was not prepared to give a death toll, calling it "a very fluid situation."

He told reporters police were flooding the streets as they sought the gunman.

"We have literally hundreds of police officers working around the state of Maine to investigate this case, to locate Mr. Card," he told reporters.

Rescue vehicles rushed in from around central Maine to tend to the wounded, city councilor McCarthy said, and the two Lewiston hospitals "have called in every off-duty staff member that they could to deal with this."

President Joe Biden made calls — stepping away from a state dinner honoring Australia's prime minister — to Maine's governor, its two senators and a local congressman to offer federal support, the White House said.

Early on Thursday, armed police were seen guarding the Central Maine Medical Center, where some of the wounded were being treated.

Several Maine school boards and educational institutions, including Bates College, said they would not be holding classes on Thursday, according to statements.

Multiple locations

Police and rescuers reportedly arrived at the Sparetime Recreation bowling alley at about 7:15 pm local time (00:15 Thursday GMT) in response to an active shooter, and then received reports of another shooting at the Schemengees Bar & Grille, according to the Sun Journal local newspaper.

Police issued a number of photographs of 40-year-old Card at the bowling alley, where he appears calm and composed as he moves through the doorway with his rifle raised.

"Please contact law enforcement if you are aware of his whereabouts," they said.

Sauschuck said officers had located a "vehicle of interest" they had been looking for — a white sport utility vehicle (SUV) — in Lisbon, a town around eight miles (12 kilometers) from Lewiston, where residents had also been warned to stay off the streets.

Card was not in the vehicle, reports said.

Law enforcement "are investigating two active shooter events," the Androscoggin County Sheriff's Department said on social media.

"We are encouraging all businesses to lock down and or close while we investigate. The suspect is still at large."

Maine Governor Janet Mills said she was "aware of and have been briefed on the active shooter situation in Lewiston."

CNN reported that at least 50 people were wounded in the incidents, citing multiple law enforcement sources, but said it was unclear how many of the injuries were the result of gunfire.

It was unclear if initial reports of shots being fired at a third site, a Walmart distribution center, were accurate.

My hometown

Maine Congressman Jared Golden wrote on social media that "like all Mainers, I'm horrified by the events in Lewison tonight. This is my hometown."

"Right now, all of us are looking to local law enforcement as they gain control of the situation and gather information. Our hearts break for those who are affected," he said.

Distraught citizens flocked to local hospitals.

"I'm just overwhelmed. I've been here trying to spread, you know, some kind of comfort, some kind of support," Cynthia Hunter, a local resident, told CBS affiliate WGME.

The shooting is one of the deadliest since 2017, when a gunman opened fire on a crowded music festival in Las Vegas, killing about 60 people.

Gun violence is alarmingly common in the United States, a country where there are more guns than people and where attempts to clamp down on their spread are always met with stiff resistance.

The United States has recorded over 500 mass shootings this year, according to the Gun Violence Archive (GVA), a non-governmental organization that defines a mass shooting as four or more people wounded or killed.

Wednesday's attack was the deadliest mass shooting in 2023 so far, according to the GVA's data.

Efforts to tighten gun controls have for years run up against opposition from Republicans, staunch defenders of the constitutional right to bear arms. 

The political paralysis endures despite widespread outrage over recurring shootings.

Lewiston is the second most populous city in Maine located some 30 miles north of the largest city, Portland.