A massive, multi-agency search is underway in the Northwest Alaska city of Kotzebue for a 10-year-old girl who vanished two days ago, officials said.

Ashley Johnson-Barr, 10, did not return home after going outside to play Thursday afternoon, said Clement Richards Sr., mayor of the Northwest Arctic Borough.

She was last seen at about 5:30 p.m. that day, at the Rainbow Park playground, the mayor said. Her family reported her missing when they couldn't find her.

"I'm deeply concerned she hasn't been found yet," Richards said. "We're a small community where everyone knows everyone, so were trying as hard as we can to find her."

Richards said up to 50 people have been involved in the search at any one time. That includes volunteers and local authorities going door-to-door with pictures of the dark-haired girl, and searching through abandoned buildings.

The U.S. Coast Guard has flown two helicopters searching for Barr, including over waters outside the city of about 3,200 along the Chukchi Sea.

Alaska State Troopers are coordinating search efforts, using the borough's assembly chambers as an incident center, he said. The agency's incident management team arrived Saturday morning.

Volunteers on four-wheelers are scouring streets and the tundra outside the village. Other volunteers are operating boats and planes to help, the mayor said.

Borough Assembly President Nasruk Carl Weisner said search teams have been assigned to different sections of Kotzebue. Weisner, a member of the Arctic Circle Search and Rescue volunteers, said he was searching by four-wheeler.

"It's a very deliberate effort," Weisner said.

(Ashley Johnson-Barr) "comes from a very caring family," he said. "The community has really, really come together as they always do at times like this. We're going to continue searching until she's found safe."

Asked if any foul play is suspected, Richards said the community is trying to stay focused on the search.