(AP) — At least 18 people were killed in shootings at a restaurant and a bowling alley in Lewiston, Maine, on Wednesday night, sparking a massive search for the suspect.

Late Thursday, heavily armed law enforcement backed by a police helicopter had surrounded a home and told anyone who might be inside to surrender, but authorities eventually left without indicating anyone had been taken into custody.

On Friday, investigators continue to work at the two shooting scenes and divers are expected to join the effort along the Androscoggin River, near where the suspect’s car was found.

INVESTIGATORS RECEIVE MORE THAN 500 TIPS IN SEARCH FOR SHOOTING SUSPECT

Investigators in Maine have received more than 500 tips as they prepare to add river divers to the massive search for the suspect in the Lewiston mass killing.

Investigators are checking those tips off their list as they work, Maine Department of Public Safety Commissioner Michael Sauschuck said at a news conference Friday morning.

People can expect to see investigators at the two shooting scenes — a restaurant and a bowling alley — in the coming days as they process “every square inch of these facilities,” he said.

In addition to those sites, he said divers and other investigators will be searching Friday at the Androscoggin River, near where suspect Robert Card’s car was found.

“We are on 24 hours, and we will be, until the suspect in this case is brought to justice,” Sauschuck said.

Sauschuck said police were evaluating whether shelter-in-place orders for several communities need to be changed Friday.

SEARCH FOR SUSPECT IN SHOOTING PROMPTS DREAD IN MAINE

The ongoing search for Robert Card, an Army reservist who authorities say fatally shot 18 people at a bowling alley and a bar in Maine, has prompted dread around the state.

Much of Thursday’s search focused on a large property belonging to one of Card’s relatives in rural Bowdoin, where concerned locals said Card could have the upper hand in navigating the rural, wooded area that he knows well.

In Portland, some restaurants and bars closed their doors, bringing an unusual early evening quiet to the typically bustling downtown of the state’s largest city.

One popular seafood joint posted a sign on its door saying it would remain closed while the staff awaited word on the search. Another restaurant canceled reservations Thursday “for the safety of our guests and staff.”

LEWISTON SCHOOLS WILL BE CLOSED FRIDAY, SUPERINTENDENT SAYS

LEWISTON, Maine — Lewiston Public Schools will be closed again on Friday, according to a post by Superintendent Jake Langlais on the district’s website.

“We remain in a shelter-in-place situation,” the post said. “We will not open buildings or run bus transportation.”

The superintendent said students and staff have been directly impacted by the shooting and the events since 7 p.m. Wednesday are “unimaginable.”

School officials in Maine’s largest city of Portland will decide by 5 a.m. Friday whether to open based on information received from police, according to a post on the district’s website.

Bates College in Lewiston also canceled classes Friday and postponed the inauguration of the school’s first Black president, Garry Jenkins, the school’s website said.