By Gabriella Borter

LEWISTON, Maine (Reuters) -Police in Maine extended their round-the-clock search into Friday for U.S. army reservist Robert R. Card, their main suspect in a mass shooting on Wednesday at a bar and bowling alley in Lewiston in which 18 people were killed and 13 were injured.

Officials urged tens of thousands of area residents to stay indoors for their safety.

Part of the search played out on live television Thursday night when officials executed several search warrants in the neighboring town of Bowdoin, Maine, where Card lives.

Law enforcement officials surrounded Card's house in the woods for more than two hours, with an FBI agent issuing orders over a bullhorn to "come out with your hands up," but apparently nobody was inside.

Police did not know if Card was inside when the effort began and the amplified messages were "standard search warrant announcements," a Maine Department of Public Safety spokesperson said.

Lewiston, a former textile hub of 38,000 people on the banks of the Androscoggin River, and neighboring communities have been largely shut down since the Wednesday evening attacks to enable hundreds of officers to conduct their search. Colleges and public schools in the area canceled classes for a second day.

There were almost no cars on the roads, just a few people outside, and many businesses in downtown Lewiston were closed. Security agents with rifles and bulletproof vests guarded the hospital where many of the shooting victims were taken.

Card, 40, is a sergeant at a nearby U.S. Army Reserve base who law enforcement officials said had been temporarily committed to a mental health facility over the summer.

On the night of the shootings, Maine State Police found a white SUV they believe Card used to get away parked at a boat launch in Lisbon, Maine, about 7 miles (11 km) to the southeast of Lewiston. Public records show he owns at least one watercraft made by Sea-Doo, a company known for its jet skis.

The bloodshed rattled towns throughout Androscoggin County that were under shelter-in-place orders as they joined the growing list of U.S. communities to suffer from a gun massacre.

"It's a small town. You get to know everybody," said Ken Spalding of Lisbon. "But I had told my wife a couple of years ago, 'It's not if, my dear. It's when.'"

The number of U.S. shootings in which four or more people are shot is projected to reach 679 in 2023, up from 647 in 2022, according to data from the Gun Violence Archive.

The number of people killed in Wednesday's attacks is close to the annual number of homicides that normally occur in Maine, which has fluctuated between 16 and 29 since 2012, according to Maine State Police.

14-YEAR-OLD BOY AMONG DEAD

The victims included Bill Young and his 14-year-old son Aaron, who were shot and killed at the Just-In-Time Recreation bowling alley, Bill's brother Rob Young told Reuters.

Also among the dead was Bryan MacFarlane, 40, a member of a deaf community group participating in a cornhole tournament at Schemengees Bar & Grille when he was killed, his sister Keri Brooks told CNN.

Guns are lightly regulated in Maine, where about half of all adults live in a household with a firearm, according to a 2020 study by RAND Corporation.

Maine does not require a permit to buy or carry a gun, and it does not have so-called "red flag" laws seen in some other states that allow law enforcement to temporarily disarm people deemed to be dangerous.

U.S. Representative Jared Golden, a Democrat from Lewiston, told reporters that the attacks have reversed his opposition to banning certain kinds of semi-automatic rifles.

"I now call on the United States Congress to ban assault rifles, like the one used by the perpetrator of this mass killing in my hometown," Golden told a news conference.

But Congress has been mostly unable to pass gun control, even after previous tragedies such as the 2012 massacre at Sandy Hook Elementary School in Newtown, Connecticut, where 20 first-graders and six adults were gunned down.

A landmark 2022 U.S. Supreme Court ruling has made it more difficult to pass gun laws. The court found that individuals have a constitutional right to carry weapons in public, and that lawmakers can only pass gun regulations that resemble those that existed in the United States in the 18th century.

(Reporting by Gabriella Borter and Richard Valdmanis in Lewiston; Additional reporting by Nick Pfosi in Lewiston and Lisbon, Maine, and by Rich McKay; Writing by Daniel Trotta and Jonathan Allen; Editing by Stephen Coates and Mark Porter)